{
  "contractName": "SafeMath",
  "abi": [],
  "metadata": "{\"compiler\":{\"version\":\"0.6.12+commit.27d51765\"},\"language\":\"Solidity\",\"output\":{\"abi\":[],\"devdoc\":{\"details\":\"Wrappers over Solidity's arithmetic operations with added overflow checks. Arithmetic operations in Solidity wrap on overflow. This can easily result in bugs, because programmers usually assume that an overflow raises an error, which is the standard behavior in high level programming languages. `SafeMath` restores this intuition by reverting the transaction when an operation overflows. Using this library instead of the unchecked operations eliminates an entire class of bugs, so it's recommended to use it always.\",\"kind\":\"dev\",\"methods\":{},\"version\":1},\"userdoc\":{\"kind\":\"user\",\"methods\":{},\"version\":1}},\"settings\":{\"compilationTarget\":{\"@openzeppelin/contracts/math/SafeMath.sol\":\"SafeMath\"},\"evmVersion\":\"istanbul\",\"libraries\":{},\"metadata\":{\"bytecodeHash\":\"ipfs\"},\"optimizer\":{\"enabled\":true,\"runs\":200},\"remappings\":[]},\"sources\":{\"@openzeppelin/contracts/math/SafeMath.sol\":{\"keccak256\":\"0x3b21f2c8d626de3b9925ae33e972d8bf5c8b1bffb3f4ee94daeed7d0679036e6\",\"license\":\"MIT\",\"urls\":[\"bzz-raw://7f8d45329fecbf0836ad7543330c3ecd0f8d0ffa42d4016278c3eb2215fdcdfe\",\"dweb:/ipfs/QmXWLT7GcnHtA5NiD6MFi2CV3EWJY4wv5mLNnypqYDrxL3\"]}},\"version\":1}",
  "bytecode": "0x60566023600b82828239805160001a607314601657fe5b30600052607381538281f3fe73000000000000000000000000000000000000000030146080604052600080fdfea26469706673582212203de63fabaeea0171d00feccb42ca4d71fdc9a562f8c5d9a4c1affaea99f5e0a964736f6c634300060c0033",
  "deployedBytecode": "0x73000000000000000000000000000000000000000030146080604052600080fdfea26469706673582212203de63fabaeea0171d00feccb42ca4d71fdc9a562f8c5d9a4c1affaea99f5e0a964736f6c634300060c0033",
  "immutableReferences": {},
  "sourceMap": "630:4578:12:-:0;;;;;;;;;;;;;;;;;;;;;;;;;",
  "deployedSourceMap": "630:4578:12:-:0;;;;;;;;",
  "source": "// SPDX-License-Identifier: MIT\n\npragma solidity >=0.6.0 <0.8.0;\n\n/**\n * @dev Wrappers over Solidity's arithmetic operations with added overflow\n * checks.\n *\n * Arithmetic operations in Solidity wrap on overflow. This can easily result\n * in bugs, because programmers usually assume that an overflow raises an\n * error, which is the standard behavior in high level programming languages.\n * `SafeMath` restores this intuition by reverting the transaction when an\n * operation overflows.\n *\n * Using this library instead of the unchecked operations eliminates an entire\n * class of bugs, so it's recommended to use it always.\n */\nlibrary SafeMath {\n    /**\n     * @dev Returns the addition of two unsigned integers, reverting on\n     * overflow.\n     *\n     * Counterpart to Solidity's `+` operator.\n     *\n     * Requirements:\n     *\n     * - Addition cannot overflow.\n     */\n    function add(uint256 a, uint256 b) internal pure returns (uint256) {\n        uint256 c = a + b;\n        require(c >= a, \"SafeMath: addition overflow\");\n\n        return c;\n    }\n\n    /**\n     * @dev Returns the subtraction of two unsigned integers, reverting on\n     * overflow (when the result is negative).\n     *\n     * Counterpart to Solidity's `-` operator.\n     *\n     * Requirements:\n     *\n     * - Subtraction cannot overflow.\n     */\n    function sub(uint256 a, uint256 b) internal pure returns (uint256) {\n        return sub(a, b, \"SafeMath: subtraction overflow\");\n    }\n\n    /**\n     * @dev Returns the subtraction of two unsigned integers, reverting with custom message on\n     * overflow (when the result is negative).\n     *\n     * Counterpart to Solidity's `-` operator.\n     *\n     * Requirements:\n     *\n     * - Subtraction cannot overflow.\n     */\n    function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {\n        require(b <= a, errorMessage);\n        uint256 c = a - b;\n\n        return c;\n    }\n\n    /**\n     * @dev Returns the multiplication of two unsigned integers, reverting on\n     * overflow.\n     *\n     * Counterpart to Solidity's `*` operator.\n     *\n     * Requirements:\n     *\n     * - Multiplication cannot overflow.\n     */\n    function mul(uint256 a, uint256 b) internal pure returns (uint256) {\n        // Gas optimization: this is cheaper than requiring 'a' not being zero, but the\n        // benefit is lost if 'b' is also tested.\n        // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522\n        if (a == 0) {\n            return 0;\n        }\n\n        uint256 c = a * b;\n        require(c / a == b, \"SafeMath: multiplication overflow\");\n\n        return c;\n    }\n\n    /**\n     * @dev Returns the integer division of two unsigned integers. Reverts on\n     * division by zero. The result is rounded towards zero.\n     *\n     * Counterpart to Solidity's `/` operator. Note: this function uses a\n     * `revert` opcode (which leaves remaining gas untouched) while Solidity\n     * uses an invalid opcode to revert (consuming all remaining gas).\n     *\n     * Requirements:\n     *\n     * - The divisor cannot be zero.\n     */\n    function div(uint256 a, uint256 b) internal pure returns (uint256) {\n        return div(a, b, \"SafeMath: division by zero\");\n    }\n\n    /**\n     * @dev Returns the integer division of two unsigned integers. Reverts with custom message on\n     * division by zero. The result is rounded towards zero.\n     *\n     * Counterpart to Solidity's `/` operator. Note: this function uses a\n     * `revert` opcode (which leaves remaining gas untouched) while Solidity\n     * uses an invalid opcode to revert (consuming all remaining gas).\n     *\n     * Requirements:\n     *\n     * - The divisor cannot be zero.\n     */\n    function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {\n        require(b > 0, errorMessage);\n        uint256 c = a / b;\n        // assert(a == b * c + a % b); // There is no case in which this doesn't hold\n\n        return c;\n    }\n\n    /**\n     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),\n     * Reverts when dividing by zero.\n     *\n     * Counterpart to Solidity's `%` operator. This function uses a `revert`\n     * opcode (which leaves remaining gas untouched) while Solidity uses an\n     * invalid opcode to revert (consuming all remaining gas).\n     *\n     * Requirements:\n     *\n     * - The divisor cannot be zero.\n     */\n    function mod(uint256 a, uint256 b) internal pure returns (uint256) {\n        return mod(a, b, \"SafeMath: modulo by zero\");\n    }\n\n    /**\n     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),\n     * Reverts with custom message when dividing by zero.\n     *\n     * Counterpart to Solidity's `%` operator. This function uses a `revert`\n     * opcode (which leaves remaining gas untouched) while Solidity uses an\n     * invalid opcode to revert (consuming all remaining gas).\n     *\n     * Requirements:\n     *\n     * - The divisor cannot be zero.\n     */\n    function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {\n        require(b != 0, errorMessage);\n        return a % b;\n    }\n}\n",
  "sourcePath": "@openzeppelin/contracts/math/SafeMath.sol",
  "ast": {
    "absolutePath": "@openzeppelin/contracts/math/SafeMath.sol",
    "exportedSymbols": {
      "SafeMath": [
        2752
      ]
    },
    "id": 2753,
    "license": "MIT",
    "nodeType": "SourceUnit",
    "nodes": [
      {
        "id": 2558,
        "literals": [
          "solidity",
          ">=",
          "0.6",
          ".0",
          "<",
          "0.8",
          ".0"
        ],
        "nodeType": "PragmaDirective",
        "src": "33:31:12"
      },
      {
        "abstract": false,
        "baseContracts": [],
        "contractDependencies": [],
        "contractKind": "library",
        "documentation": {
          "id": 2559,
          "nodeType": "StructuredDocumentation",
          "src": "66:563:12",
          "text": " @dev Wrappers over Solidity's arithmetic operations with added overflow\n checks.\n Arithmetic operations in Solidity wrap on overflow. This can easily result\n in bugs, because programmers usually assume that an overflow raises an\n error, which is the standard behavior in high level programming languages.\n `SafeMath` restores this intuition by reverting the transaction when an\n operation overflows.\n Using this library instead of the unchecked operations eliminates an entire\n class of bugs, so it's recommended to use it always."
        },
        "fullyImplemented": true,
        "id": 2752,
        "linearizedBaseContracts": [
          2752
        ],
        "name": "SafeMath",
        "nodeType": "ContractDefinition",
        "nodes": [
          {
            "body": {
              "id": 2584,
              "nodeType": "Block",
              "src": "949:109:12",
              "statements": [
                {
                  "assignments": [
                    2570
                  ],
                  "declarations": [
                    {
                      "constant": false,
                      "id": 2570,
                      "mutability": "mutable",
                      "name": "c",
                      "nodeType": "VariableDeclaration",
                      "overrides": null,
                      "scope": 2584,
                      "src": "959:9:12",
                      "stateVariable": false,
                      "storageLocation": "default",
                      "typeDescriptions": {
                        "typeIdentifier": "t_uint256",
                        "typeString": "uint256"
                      },
                      "typeName": {
                        "id": 2569,
                        "name": "uint256",
                        "nodeType": "ElementaryTypeName",
                        "src": "959:7:12",
                        "typeDescriptions": {
                          "typeIdentifier": "t_uint256",
                          "typeString": "uint256"
                        }
                      },
                      "value": null,
                      "visibility": "internal"
                    }
                  ],
                  "id": 2574,
                  "initialValue": {
                    "argumentTypes": null,
                    "commonType": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    },
                    "id": 2573,
                    "isConstant": false,
                    "isLValue": false,
                    "isPure": false,
                    "lValueRequested": false,
                    "leftExpression": {
                      "argumentTypes": null,
                      "id": 2571,
                      "name": "a",
                      "nodeType": "Identifier",
                      "overloadedDeclarations": [],
                      "referencedDeclaration": 2562,
                      "src": "971:1:12",
                      "typeDescriptions": {
                        "typeIdentifier": "t_uint256",
                        "typeString": "uint256"
                      }
                    },
                    "nodeType": "BinaryOperation",
                    "operator": "+",
                    "rightExpression": {
                      "argumentTypes": null,
                      "id": 2572,
                      "name": "b",
                      "nodeType": "Identifier",
                      "overloadedDeclarations": [],
                      "referencedDeclaration": 2564,
                      "src": "975:1:12",
                      "typeDescriptions": {
                        "typeIdentifier": "t_uint256",
                        "typeString": "uint256"
                      }
                    },
                    "src": "971:5:12",
                    "typeDescriptions": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    }
                  },
                  "nodeType": "VariableDeclarationStatement",
                  "src": "959:17:12"
                },
                {
                  "expression": {
                    "argumentTypes": null,
                    "arguments": [
                      {
                        "argumentTypes": null,
                        "commonType": {
                          "typeIdentifier": "t_uint256",
                          "typeString": "uint256"
                        },
                        "id": 2578,
                        "isConstant": false,
                        "isLValue": false,
                        "isPure": false,
                        "lValueRequested": false,
                        "leftExpression": {
                          "argumentTypes": null,
                          "id": 2576,
                          "name": "c",
                          "nodeType": "Identifier",
                          "overloadedDeclarations": [],
                          "referencedDeclaration": 2570,
                          "src": "994:1:12",
                          "typeDescriptions": {
                            "typeIdentifier": "t_uint256",
                            "typeString": "uint256"
                          }
                        },
                        "nodeType": "BinaryOperation",
                        "operator": ">=",
                        "rightExpression": {
                          "argumentTypes": null,
                          "id": 2577,
                          "name": "a",
                          "nodeType": "Identifier",
                          "overloadedDeclarations": [],
                          "referencedDeclaration": 2562,
                          "src": "999:1:12",
                          "typeDescriptions": {
                            "typeIdentifier": "t_uint256",
                            "typeString": "uint256"
                          }
                        },
                        "src": "994:6:12",
                        "typeDescriptions": {
                          "typeIdentifier": "t_bool",
                          "typeString": "bool"
                        }
                      },
                      {
                        "argumentTypes": null,
                        "hexValue": "536166654d6174683a206164646974696f6e206f766572666c6f77",
                        "id": 2579,
                        "isConstant": false,
                        "isLValue": false,
                        "isPure": true,
                        "kind": "string",
                        "lValueRequested": false,
                        "nodeType": "Literal",
                        "src": "1002:29:12",
                        "subdenomination": null,
                        "typeDescriptions": {
                          "typeIdentifier": "t_stringliteral_30cc447bcc13b3e22b45cef0dd9b0b514842d836dd9b6eb384e20dedfb47723a",
                          "typeString": "literal_string \"SafeMath: addition overflow\""
                        },
                        "value": "SafeMath: addition overflow"
                      }
                    ],
                    "expression": {
                      "argumentTypes": [
                        {
                          "typeIdentifier": "t_bool",
                          "typeString": "bool"
                        },
                        {
                          "typeIdentifier": "t_stringliteral_30cc447bcc13b3e22b45cef0dd9b0b514842d836dd9b6eb384e20dedfb47723a",
                          "typeString": "literal_string \"SafeMath: addition overflow\""
                        }
                      ],
                      "id": 2575,
                      "name": "require",
                      "nodeType": "Identifier",
                      "overloadedDeclarations": [
                        -18,
                        -18
                      ],
                      "referencedDeclaration": -18,
                      "src": "986:7:12",
                      "typeDescriptions": {
                        "typeIdentifier": "t_function_require_pure$_t_bool_$_t_string_memory_ptr_$returns$__$",
                        "typeString": "function (bool,string memory) pure"
                      }
                    },
                    "id": 2580,
                    "isConstant": false,
                    "isLValue": false,
                    "isPure": false,
                    "kind": "functionCall",
                    "lValueRequested": false,
                    "names": [],
                    "nodeType": "FunctionCall",
                    "src": "986:46:12",
                    "tryCall": false,
                    "typeDescriptions": {
                      "typeIdentifier": "t_tuple$__$",
                      "typeString": "tuple()"
                    }
                  },
                  "id": 2581,
                  "nodeType": "ExpressionStatement",
                  "src": "986:46:12"
                },
                {
                  "expression": {
                    "argumentTypes": null,
                    "id": 2582,
                    "name": "c",
                    "nodeType": "Identifier",
                    "overloadedDeclarations": [],
                    "referencedDeclaration": 2570,
                    "src": "1050:1:12",
                    "typeDescriptions": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    }
                  },
                  "functionReturnParameters": 2568,
                  "id": 2583,
                  "nodeType": "Return",
                  "src": "1043:8:12"
                }
              ]
            },
            "documentation": {
              "id": 2560,
              "nodeType": "StructuredDocumentation",
              "src": "653:224:12",
              "text": " @dev Returns the addition of two unsigned integers, reverting on\n overflow.\n Counterpart to Solidity's `+` operator.\n Requirements:\n - Addition cannot overflow."
            },
            "id": 2585,
            "implemented": true,
            "kind": "function",
            "modifiers": [],
            "name": "add",
            "nodeType": "FunctionDefinition",
            "overrides": null,
            "parameters": {
              "id": 2565,
              "nodeType": "ParameterList",
              "parameters": [
                {
                  "constant": false,
                  "id": 2562,
                  "mutability": "mutable",
                  "name": "a",
                  "nodeType": "VariableDeclaration",
                  "overrides": null,
                  "scope": 2585,
                  "src": "895:9:12",
                  "stateVariable": false,
                  "storageLocation": "default",
                  "typeDescriptions": {
                    "typeIdentifier": "t_uint256",
                    "typeString": "uint256"
                  },
                  "typeName": {
                    "id": 2561,
                    "name": "uint256",
                    "nodeType": "ElementaryTypeName",
                    "src": "895:7:12",
                    "typeDescriptions": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    }
                  },
                  "value": null,
                  "visibility": "internal"
                },
                {
                  "constant": false,
                  "id": 2564,
                  "mutability": "mutable",
                  "name": "b",
                  "nodeType": "VariableDeclaration",
                  "overrides": null,
                  "scope": 2585,
                  "src": "906:9:12",
                  "stateVariable": false,
                  "storageLocation": "default",
                  "typeDescriptions": {
                    "typeIdentifier": "t_uint256",
                    "typeString": "uint256"
                  },
                  "typeName": {
                    "id": 2563,
                    "name": "uint256",
                    "nodeType": "ElementaryTypeName",
                    "src": "906:7:12",
                    "typeDescriptions": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    }
                  },
                  "value": null,
                  "visibility": "internal"
                }
              ],
              "src": "894:22:12"
            },
            "returnParameters": {
              "id": 2568,
              "nodeType": "ParameterList",
              "parameters": [
                {
                  "constant": false,
                  "id": 2567,
                  "mutability": "mutable",
                  "name": "",
                  "nodeType": "VariableDeclaration",
                  "overrides": null,
                  "scope": 2585,
                  "src": "940:7:12",
                  "stateVariable": false,
                  "storageLocation": "default",
                  "typeDescriptions": {
                    "typeIdentifier": "t_uint256",
                    "typeString": "uint256"
                  },
                  "typeName": {
                    "id": 2566,
                    "name": "uint256",
                    "nodeType": "ElementaryTypeName",
                    "src": "940:7:12",
                    "typeDescriptions": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    }
                  },
                  "value": null,
                  "visibility": "internal"
                }
              ],
              "src": "939:9:12"
            },
            "scope": 2752,
            "src": "882:176:12",
            "stateMutability": "pure",
            "virtual": false,
            "visibility": "internal"
          },
          {
            "body": {
              "id": 2601,
              "nodeType": "Block",
              "src": "1396:67:12",
              "statements": [
                {
                  "expression": {
                    "argumentTypes": null,
                    "arguments": [
                      {
                        "argumentTypes": null,
                        "id": 2596,
                        "name": "a",
                        "nodeType": "Identifier",
                        "overloadedDeclarations": [],
                        "referencedDeclaration": 2588,
                        "src": "1417:1:12",
                        "typeDescriptions": {
                          "typeIdentifier": "t_uint256",
                          "typeString": "uint256"
                        }
                      },
                      {
                        "argumentTypes": null,
                        "id": 2597,
                        "name": "b",
                        "nodeType": "Identifier",
                        "overloadedDeclarations": [],
                        "referencedDeclaration": 2590,
                        "src": "1420:1:12",
                        "typeDescriptions": {
                          "typeIdentifier": "t_uint256",
                          "typeString": "uint256"
                        }
                      },
                      {
                        "argumentTypes": null,
                        "hexValue": "536166654d6174683a207375627472616374696f6e206f766572666c6f77",
                        "id": 2598,
                        "isConstant": false,
                        "isLValue": false,
                        "isPure": true,
                        "kind": "string",
                        "lValueRequested": false,
                        "nodeType": "Literal",
                        "src": "1423:32:12",
                        "subdenomination": null,
                        "typeDescriptions": {
                          "typeIdentifier": "t_stringliteral_50b058e9b5320e58880d88223c9801cd9eecdcf90323d5c2318bc1b6b916e862",
                          "typeString": "literal_string \"SafeMath: subtraction overflow\""
                        },
                        "value": "SafeMath: subtraction overflow"
                      }
                    ],
                    "expression": {
                      "argumentTypes": [
                        {
                          "typeIdentifier": "t_uint256",
                          "typeString": "uint256"
                        },
                        {
                          "typeIdentifier": "t_uint256",
                          "typeString": "uint256"
                        },
                        {
                          "typeIdentifier": "t_stringliteral_50b058e9b5320e58880d88223c9801cd9eecdcf90323d5c2318bc1b6b916e862",
                          "typeString": "literal_string \"SafeMath: subtraction overflow\""
                        }
                      ],
                      "id": 2595,
                      "name": "sub",
                      "nodeType": "Identifier",
                      "overloadedDeclarations": [
                        2602,
                        2630
                      ],
                      "referencedDeclaration": 2630,
                      "src": "1413:3:12",
                      "typeDescriptions": {
                        "typeIdentifier": "t_function_internal_pure$_t_uint256_$_t_uint256_$_t_string_memory_ptr_$returns$_t_uint256_$",
                        "typeString": "function (uint256,uint256,string memory) pure returns (uint256)"
                      }
                    },
                    "id": 2599,
                    "isConstant": false,
                    "isLValue": false,
                    "isPure": false,
                    "kind": "functionCall",
                    "lValueRequested": false,
                    "names": [],
                    "nodeType": "FunctionCall",
                    "src": "1413:43:12",
                    "tryCall": false,
                    "typeDescriptions": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    }
                  },
                  "functionReturnParameters": 2594,
                  "id": 2600,
                  "nodeType": "Return",
                  "src": "1406:50:12"
                }
              ]
            },
            "documentation": {
              "id": 2586,
              "nodeType": "StructuredDocumentation",
              "src": "1064:260:12",
              "text": " @dev Returns the subtraction of two unsigned integers, reverting on\n overflow (when the result is negative).\n Counterpart to Solidity's `-` operator.\n Requirements:\n - Subtraction cannot overflow."
            },
            "id": 2602,
            "implemented": true,
            "kind": "function",
            "modifiers": [],
            "name": "sub",
            "nodeType": "FunctionDefinition",
            "overrides": null,
            "parameters": {
              "id": 2591,
              "nodeType": "ParameterList",
              "parameters": [
                {
                  "constant": false,
                  "id": 2588,
                  "mutability": "mutable",
                  "name": "a",
                  "nodeType": "VariableDeclaration",
                  "overrides": null,
                  "scope": 2602,
                  "src": "1342:9:12",
                  "stateVariable": false,
                  "storageLocation": "default",
                  "typeDescriptions": {
                    "typeIdentifier": "t_uint256",
                    "typeString": "uint256"
                  },
                  "typeName": {
                    "id": 2587,
                    "name": "uint256",
                    "nodeType": "ElementaryTypeName",
                    "src": "1342:7:12",
                    "typeDescriptions": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    }
                  },
                  "value": null,
                  "visibility": "internal"
                },
                {
                  "constant": false,
                  "id": 2590,
                  "mutability": "mutable",
                  "name": "b",
                  "nodeType": "VariableDeclaration",
                  "overrides": null,
                  "scope": 2602,
                  "src": "1353:9:12",
                  "stateVariable": false,
                  "storageLocation": "default",
                  "typeDescriptions": {
                    "typeIdentifier": "t_uint256",
                    "typeString": "uint256"
                  },
                  "typeName": {
                    "id": 2589,
                    "name": "uint256",
                    "nodeType": "ElementaryTypeName",
                    "src": "1353:7:12",
                    "typeDescriptions": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    }
                  },
                  "value": null,
                  "visibility": "internal"
                }
              ],
              "src": "1341:22:12"
            },
            "returnParameters": {
              "id": 2594,
              "nodeType": "ParameterList",
              "parameters": [
                {
                  "constant": false,
                  "id": 2593,
                  "mutability": "mutable",
                  "name": "",
                  "nodeType": "VariableDeclaration",
                  "overrides": null,
                  "scope": 2602,
                  "src": "1387:7:12",
                  "stateVariable": false,
                  "storageLocation": "default",
                  "typeDescriptions": {
                    "typeIdentifier": "t_uint256",
                    "typeString": "uint256"
                  },
                  "typeName": {
                    "id": 2592,
                    "name": "uint256",
                    "nodeType": "ElementaryTypeName",
                    "src": "1387:7:12",
                    "typeDescriptions": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    }
                  },
                  "value": null,
                  "visibility": "internal"
                }
              ],
              "src": "1386:9:12"
            },
            "scope": 2752,
            "src": "1329:134:12",
            "stateMutability": "pure",
            "virtual": false,
            "visibility": "internal"
          },
          {
            "body": {
              "id": 2629,
              "nodeType": "Block",
              "src": "1849:92:12",
              "statements": [
                {
                  "expression": {
                    "argumentTypes": null,
                    "arguments": [
                      {
                        "argumentTypes": null,
                        "commonType": {
                          "typeIdentifier": "t_uint256",
                          "typeString": "uint256"
                        },
                        "id": 2617,
                        "isConstant": false,
                        "isLValue": false,
                        "isPure": false,
                        "lValueRequested": false,
                        "leftExpression": {
                          "argumentTypes": null,
                          "id": 2615,
                          "name": "b",
                          "nodeType": "Identifier",
                          "overloadedDeclarations": [],
                          "referencedDeclaration": 2607,
                          "src": "1867:1:12",
                          "typeDescriptions": {
                            "typeIdentifier": "t_uint256",
                            "typeString": "uint256"
                          }
                        },
                        "nodeType": "BinaryOperation",
                        "operator": "<=",
                        "rightExpression": {
                          "argumentTypes": null,
                          "id": 2616,
                          "name": "a",
                          "nodeType": "Identifier",
                          "overloadedDeclarations": [],
                          "referencedDeclaration": 2605,
                          "src": "1872:1:12",
                          "typeDescriptions": {
                            "typeIdentifier": "t_uint256",
                            "typeString": "uint256"
                          }
                        },
                        "src": "1867:6:12",
                        "typeDescriptions": {
                          "typeIdentifier": "t_bool",
                          "typeString": "bool"
                        }
                      },
                      {
                        "argumentTypes": null,
                        "id": 2618,
                        "name": "errorMessage",
                        "nodeType": "Identifier",
                        "overloadedDeclarations": [],
                        "referencedDeclaration": 2609,
                        "src": "1875:12:12",
                        "typeDescriptions": {
                          "typeIdentifier": "t_string_memory_ptr",
                          "typeString": "string memory"
                        }
                      }
                    ],
                    "expression": {
                      "argumentTypes": [
                        {
                          "typeIdentifier": "t_bool",
                          "typeString": "bool"
                        },
                        {
                          "typeIdentifier": "t_string_memory_ptr",
                          "typeString": "string memory"
                        }
                      ],
                      "id": 2614,
                      "name": "require",
                      "nodeType": "Identifier",
                      "overloadedDeclarations": [
                        -18,
                        -18
                      ],
                      "referencedDeclaration": -18,
                      "src": "1859:7:12",
                      "typeDescriptions": {
                        "typeIdentifier": "t_function_require_pure$_t_bool_$_t_string_memory_ptr_$returns$__$",
                        "typeString": "function (bool,string memory) pure"
                      }
                    },
                    "id": 2619,
                    "isConstant": false,
                    "isLValue": false,
                    "isPure": false,
                    "kind": "functionCall",
                    "lValueRequested": false,
                    "names": [],
                    "nodeType": "FunctionCall",
                    "src": "1859:29:12",
                    "tryCall": false,
                    "typeDescriptions": {
                      "typeIdentifier": "t_tuple$__$",
                      "typeString": "tuple()"
                    }
                  },
                  "id": 2620,
                  "nodeType": "ExpressionStatement",
                  "src": "1859:29:12"
                },
                {
                  "assignments": [
                    2622
                  ],
                  "declarations": [
                    {
                      "constant": false,
                      "id": 2622,
                      "mutability": "mutable",
                      "name": "c",
                      "nodeType": "VariableDeclaration",
                      "overrides": null,
                      "scope": 2629,
                      "src": "1898:9:12",
                      "stateVariable": false,
                      "storageLocation": "default",
                      "typeDescriptions": {
                        "typeIdentifier": "t_uint256",
                        "typeString": "uint256"
                      },
                      "typeName": {
                        "id": 2621,
                        "name": "uint256",
                        "nodeType": "ElementaryTypeName",
                        "src": "1898:7:12",
                        "typeDescriptions": {
                          "typeIdentifier": "t_uint256",
                          "typeString": "uint256"
                        }
                      },
                      "value": null,
                      "visibility": "internal"
                    }
                  ],
                  "id": 2626,
                  "initialValue": {
                    "argumentTypes": null,
                    "commonType": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    },
                    "id": 2625,
                    "isConstant": false,
                    "isLValue": false,
                    "isPure": false,
                    "lValueRequested": false,
                    "leftExpression": {
                      "argumentTypes": null,
                      "id": 2623,
                      "name": "a",
                      "nodeType": "Identifier",
                      "overloadedDeclarations": [],
                      "referencedDeclaration": 2605,
                      "src": "1910:1:12",
                      "typeDescriptions": {
                        "typeIdentifier": "t_uint256",
                        "typeString": "uint256"
                      }
                    },
                    "nodeType": "BinaryOperation",
                    "operator": "-",
                    "rightExpression": {
                      "argumentTypes": null,
                      "id": 2624,
                      "name": "b",
                      "nodeType": "Identifier",
                      "overloadedDeclarations": [],
                      "referencedDeclaration": 2607,
                      "src": "1914:1:12",
                      "typeDescriptions": {
                        "typeIdentifier": "t_uint256",
                        "typeString": "uint256"
                      }
                    },
                    "src": "1910:5:12",
                    "typeDescriptions": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    }
                  },
                  "nodeType": "VariableDeclarationStatement",
                  "src": "1898:17:12"
                },
                {
                  "expression": {
                    "argumentTypes": null,
                    "id": 2627,
                    "name": "c",
                    "nodeType": "Identifier",
                    "overloadedDeclarations": [],
                    "referencedDeclaration": 2622,
                    "src": "1933:1:12",
                    "typeDescriptions": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    }
                  },
                  "functionReturnParameters": 2613,
                  "id": 2628,
                  "nodeType": "Return",
                  "src": "1926:8:12"
                }
              ]
            },
            "documentation": {
              "id": 2603,
              "nodeType": "StructuredDocumentation",
              "src": "1469:280:12",
              "text": " @dev Returns the subtraction of two unsigned integers, reverting with custom message on\n overflow (when the result is negative).\n Counterpart to Solidity's `-` operator.\n Requirements:\n - Subtraction cannot overflow."
            },
            "id": 2630,
            "implemented": true,
            "kind": "function",
            "modifiers": [],
            "name": "sub",
            "nodeType": "FunctionDefinition",
            "overrides": null,
            "parameters": {
              "id": 2610,
              "nodeType": "ParameterList",
              "parameters": [
                {
                  "constant": false,
                  "id": 2605,
                  "mutability": "mutable",
                  "name": "a",
                  "nodeType": "VariableDeclaration",
                  "overrides": null,
                  "scope": 2630,
                  "src": "1767:9:12",
                  "stateVariable": false,
                  "storageLocation": "default",
                  "typeDescriptions": {
                    "typeIdentifier": "t_uint256",
                    "typeString": "uint256"
                  },
                  "typeName": {
                    "id": 2604,
                    "name": "uint256",
                    "nodeType": "ElementaryTypeName",
                    "src": "1767:7:12",
                    "typeDescriptions": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    }
                  },
                  "value": null,
                  "visibility": "internal"
                },
                {
                  "constant": false,
                  "id": 2607,
                  "mutability": "mutable",
                  "name": "b",
                  "nodeType": "VariableDeclaration",
                  "overrides": null,
                  "scope": 2630,
                  "src": "1778:9:12",
                  "stateVariable": false,
                  "storageLocation": "default",
                  "typeDescriptions": {
                    "typeIdentifier": "t_uint256",
                    "typeString": "uint256"
                  },
                  "typeName": {
                    "id": 2606,
                    "name": "uint256",
                    "nodeType": "ElementaryTypeName",
                    "src": "1778:7:12",
                    "typeDescriptions": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    }
                  },
                  "value": null,
                  "visibility": "internal"
                },
                {
                  "constant": false,
                  "id": 2609,
                  "mutability": "mutable",
                  "name": "errorMessage",
                  "nodeType": "VariableDeclaration",
                  "overrides": null,
                  "scope": 2630,
                  "src": "1789:26:12",
                  "stateVariable": false,
                  "storageLocation": "memory",
                  "typeDescriptions": {
                    "typeIdentifier": "t_string_memory_ptr",
                    "typeString": "string"
                  },
                  "typeName": {
                    "id": 2608,
                    "name": "string",
                    "nodeType": "ElementaryTypeName",
                    "src": "1789:6:12",
                    "typeDescriptions": {
                      "typeIdentifier": "t_string_storage_ptr",
                      "typeString": "string"
                    }
                  },
                  "value": null,
                  "visibility": "internal"
                }
              ],
              "src": "1766:50:12"
            },
            "returnParameters": {
              "id": 2613,
              "nodeType": "ParameterList",
              "parameters": [
                {
                  "constant": false,
                  "id": 2612,
                  "mutability": "mutable",
                  "name": "",
                  "nodeType": "VariableDeclaration",
                  "overrides": null,
                  "scope": 2630,
                  "src": "1840:7:12",
                  "stateVariable": false,
                  "storageLocation": "default",
                  "typeDescriptions": {
                    "typeIdentifier": "t_uint256",
                    "typeString": "uint256"
                  },
                  "typeName": {
                    "id": 2611,
                    "name": "uint256",
                    "nodeType": "ElementaryTypeName",
                    "src": "1840:7:12",
                    "typeDescriptions": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    }
                  },
                  "value": null,
                  "visibility": "internal"
                }
              ],
              "src": "1839:9:12"
            },
            "scope": 2752,
            "src": "1754:187:12",
            "stateMutability": "pure",
            "virtual": false,
            "visibility": "internal"
          },
          {
            "body": {
              "id": 2664,
              "nodeType": "Block",
              "src": "2255:392:12",
              "statements": [
                {
                  "condition": {
                    "argumentTypes": null,
                    "commonType": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    },
                    "id": 2642,
                    "isConstant": false,
                    "isLValue": false,
                    "isPure": false,
                    "lValueRequested": false,
                    "leftExpression": {
                      "argumentTypes": null,
                      "id": 2640,
                      "name": "a",
                      "nodeType": "Identifier",
                      "overloadedDeclarations": [],
                      "referencedDeclaration": 2633,
                      "src": "2487:1:12",
                      "typeDescriptions": {
                        "typeIdentifier": "t_uint256",
                        "typeString": "uint256"
                      }
                    },
                    "nodeType": "BinaryOperation",
                    "operator": "==",
                    "rightExpression": {
                      "argumentTypes": null,
                      "hexValue": "30",
                      "id": 2641,
                      "isConstant": false,
                      "isLValue": false,
                      "isPure": true,
                      "kind": "number",
                      "lValueRequested": false,
                      "nodeType": "Literal",
                      "src": "2492:1:12",
                      "subdenomination": null,
                      "typeDescriptions": {
                        "typeIdentifier": "t_rational_0_by_1",
                        "typeString": "int_const 0"
                      },
                      "value": "0"
                    },
                    "src": "2487:6:12",
                    "typeDescriptions": {
                      "typeIdentifier": "t_bool",
                      "typeString": "bool"
                    }
                  },
                  "falseBody": null,
                  "id": 2646,
                  "nodeType": "IfStatement",
                  "src": "2483:45:12",
                  "trueBody": {
                    "id": 2645,
                    "nodeType": "Block",
                    "src": "2495:33:12",
                    "statements": [
                      {
                        "expression": {
                          "argumentTypes": null,
                          "hexValue": "30",
                          "id": 2643,
                          "isConstant": false,
                          "isLValue": false,
                          "isPure": true,
                          "kind": "number",
                          "lValueRequested": false,
                          "nodeType": "Literal",
                          "src": "2516:1:12",
                          "subdenomination": null,
                          "typeDescriptions": {
                            "typeIdentifier": "t_rational_0_by_1",
                            "typeString": "int_const 0"
                          },
                          "value": "0"
                        },
                        "functionReturnParameters": 2639,
                        "id": 2644,
                        "nodeType": "Return",
                        "src": "2509:8:12"
                      }
                    ]
                  }
                },
                {
                  "assignments": [
                    2648
                  ],
                  "declarations": [
                    {
                      "constant": false,
                      "id": 2648,
                      "mutability": "mutable",
                      "name": "c",
                      "nodeType": "VariableDeclaration",
                      "overrides": null,
                      "scope": 2664,
                      "src": "2538:9:12",
                      "stateVariable": false,
                      "storageLocation": "default",
                      "typeDescriptions": {
                        "typeIdentifier": "t_uint256",
                        "typeString": "uint256"
                      },
                      "typeName": {
                        "id": 2647,
                        "name": "uint256",
                        "nodeType": "ElementaryTypeName",
                        "src": "2538:7:12",
                        "typeDescriptions": {
                          "typeIdentifier": "t_uint256",
                          "typeString": "uint256"
                        }
                      },
                      "value": null,
                      "visibility": "internal"
                    }
                  ],
                  "id": 2652,
                  "initialValue": {
                    "argumentTypes": null,
                    "commonType": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    },
                    "id": 2651,
                    "isConstant": false,
                    "isLValue": false,
                    "isPure": false,
                    "lValueRequested": false,
                    "leftExpression": {
                      "argumentTypes": null,
                      "id": 2649,
                      "name": "a",
                      "nodeType": "Identifier",
                      "overloadedDeclarations": [],
                      "referencedDeclaration": 2633,
                      "src": "2550:1:12",
                      "typeDescriptions": {
                        "typeIdentifier": "t_uint256",
                        "typeString": "uint256"
                      }
                    },
                    "nodeType": "BinaryOperation",
                    "operator": "*",
                    "rightExpression": {
                      "argumentTypes": null,
                      "id": 2650,
                      "name": "b",
                      "nodeType": "Identifier",
                      "overloadedDeclarations": [],
                      "referencedDeclaration": 2635,
                      "src": "2554:1:12",
                      "typeDescriptions": {
                        "typeIdentifier": "t_uint256",
                        "typeString": "uint256"
                      }
                    },
                    "src": "2550:5:12",
                    "typeDescriptions": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    }
                  },
                  "nodeType": "VariableDeclarationStatement",
                  "src": "2538:17:12"
                },
                {
                  "expression": {
                    "argumentTypes": null,
                    "arguments": [
                      {
                        "argumentTypes": null,
                        "commonType": {
                          "typeIdentifier": "t_uint256",
                          "typeString": "uint256"
                        },
                        "id": 2658,
                        "isConstant": false,
                        "isLValue": false,
                        "isPure": false,
                        "lValueRequested": false,
                        "leftExpression": {
                          "argumentTypes": null,
                          "commonType": {
                            "typeIdentifier": "t_uint256",
                            "typeString": "uint256"
                          },
                          "id": 2656,
                          "isConstant": false,
                          "isLValue": false,
                          "isPure": false,
                          "lValueRequested": false,
                          "leftExpression": {
                            "argumentTypes": null,
                            "id": 2654,
                            "name": "c",
                            "nodeType": "Identifier",
                            "overloadedDeclarations": [],
                            "referencedDeclaration": 2648,
                            "src": "2573:1:12",
                            "typeDescriptions": {
                              "typeIdentifier": "t_uint256",
                              "typeString": "uint256"
                            }
                          },
                          "nodeType": "BinaryOperation",
                          "operator": "/",
                          "rightExpression": {
                            "argumentTypes": null,
                            "id": 2655,
                            "name": "a",
                            "nodeType": "Identifier",
                            "overloadedDeclarations": [],
                            "referencedDeclaration": 2633,
                            "src": "2577:1:12",
                            "typeDescriptions": {
                              "typeIdentifier": "t_uint256",
                              "typeString": "uint256"
                            }
                          },
                          "src": "2573:5:12",
                          "typeDescriptions": {
                            "typeIdentifier": "t_uint256",
                            "typeString": "uint256"
                          }
                        },
                        "nodeType": "BinaryOperation",
                        "operator": "==",
                        "rightExpression": {
                          "argumentTypes": null,
                          "id": 2657,
                          "name": "b",
                          "nodeType": "Identifier",
                          "overloadedDeclarations": [],
                          "referencedDeclaration": 2635,
                          "src": "2582:1:12",
                          "typeDescriptions": {
                            "typeIdentifier": "t_uint256",
                            "typeString": "uint256"
                          }
                        },
                        "src": "2573:10:12",
                        "typeDescriptions": {
                          "typeIdentifier": "t_bool",
                          "typeString": "bool"
                        }
                      },
                      {
                        "argumentTypes": null,
                        "hexValue": "536166654d6174683a206d756c7469706c69636174696f6e206f766572666c6f77",
                        "id": 2659,
                        "isConstant": false,
                        "isLValue": false,
                        "isPure": true,
                        "kind": "string",
                        "lValueRequested": false,
                        "nodeType": "Literal",
                        "src": "2585:35:12",
                        "subdenomination": null,
                        "typeDescriptions": {
                          "typeIdentifier": "t_stringliteral_9113bb53c2876a3805b2c9242029423fc540a728243ce887ab24c82cf119fba3",
                          "typeString": "literal_string \"SafeMath: multiplication overflow\""
                        },
                        "value": "SafeMath: multiplication overflow"
                      }
                    ],
                    "expression": {
                      "argumentTypes": [
                        {
                          "typeIdentifier": "t_bool",
                          "typeString": "bool"
                        },
                        {
                          "typeIdentifier": "t_stringliteral_9113bb53c2876a3805b2c9242029423fc540a728243ce887ab24c82cf119fba3",
                          "typeString": "literal_string \"SafeMath: multiplication overflow\""
                        }
                      ],
                      "id": 2653,
                      "name": "require",
                      "nodeType": "Identifier",
                      "overloadedDeclarations": [
                        -18,
                        -18
                      ],
                      "referencedDeclaration": -18,
                      "src": "2565:7:12",
                      "typeDescriptions": {
                        "typeIdentifier": "t_function_require_pure$_t_bool_$_t_string_memory_ptr_$returns$__$",
                        "typeString": "function (bool,string memory) pure"
                      }
                    },
                    "id": 2660,
                    "isConstant": false,
                    "isLValue": false,
                    "isPure": false,
                    "kind": "functionCall",
                    "lValueRequested": false,
                    "names": [],
                    "nodeType": "FunctionCall",
                    "src": "2565:56:12",
                    "tryCall": false,
                    "typeDescriptions": {
                      "typeIdentifier": "t_tuple$__$",
                      "typeString": "tuple()"
                    }
                  },
                  "id": 2661,
                  "nodeType": "ExpressionStatement",
                  "src": "2565:56:12"
                },
                {
                  "expression": {
                    "argumentTypes": null,
                    "id": 2662,
                    "name": "c",
                    "nodeType": "Identifier",
                    "overloadedDeclarations": [],
                    "referencedDeclaration": 2648,
                    "src": "2639:1:12",
                    "typeDescriptions": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    }
                  },
                  "functionReturnParameters": 2639,
                  "id": 2663,
                  "nodeType": "Return",
                  "src": "2632:8:12"
                }
              ]
            },
            "documentation": {
              "id": 2631,
              "nodeType": "StructuredDocumentation",
              "src": "1947:236:12",
              "text": " @dev Returns the multiplication of two unsigned integers, reverting on\n overflow.\n Counterpart to Solidity's `*` operator.\n Requirements:\n - Multiplication cannot overflow."
            },
            "id": 2665,
            "implemented": true,
            "kind": "function",
            "modifiers": [],
            "name": "mul",
            "nodeType": "FunctionDefinition",
            "overrides": null,
            "parameters": {
              "id": 2636,
              "nodeType": "ParameterList",
              "parameters": [
                {
                  "constant": false,
                  "id": 2633,
                  "mutability": "mutable",
                  "name": "a",
                  "nodeType": "VariableDeclaration",
                  "overrides": null,
                  "scope": 2665,
                  "src": "2201:9:12",
                  "stateVariable": false,
                  "storageLocation": "default",
                  "typeDescriptions": {
                    "typeIdentifier": "t_uint256",
                    "typeString": "uint256"
                  },
                  "typeName": {
                    "id": 2632,
                    "name": "uint256",
                    "nodeType": "ElementaryTypeName",
                    "src": "2201:7:12",
                    "typeDescriptions": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    }
                  },
                  "value": null,
                  "visibility": "internal"
                },
                {
                  "constant": false,
                  "id": 2635,
                  "mutability": "mutable",
                  "name": "b",
                  "nodeType": "VariableDeclaration",
                  "overrides": null,
                  "scope": 2665,
                  "src": "2212:9:12",
                  "stateVariable": false,
                  "storageLocation": "default",
                  "typeDescriptions": {
                    "typeIdentifier": "t_uint256",
                    "typeString": "uint256"
                  },
                  "typeName": {
                    "id": 2634,
                    "name": "uint256",
                    "nodeType": "ElementaryTypeName",
                    "src": "2212:7:12",
                    "typeDescriptions": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    }
                  },
                  "value": null,
                  "visibility": "internal"
                }
              ],
              "src": "2200:22:12"
            },
            "returnParameters": {
              "id": 2639,
              "nodeType": "ParameterList",
              "parameters": [
                {
                  "constant": false,
                  "id": 2638,
                  "mutability": "mutable",
                  "name": "",
                  "nodeType": "VariableDeclaration",
                  "overrides": null,
                  "scope": 2665,
                  "src": "2246:7:12",
                  "stateVariable": false,
                  "storageLocation": "default",
                  "typeDescriptions": {
                    "typeIdentifier": "t_uint256",
                    "typeString": "uint256"
                  },
                  "typeName": {
                    "id": 2637,
                    "name": "uint256",
                    "nodeType": "ElementaryTypeName",
                    "src": "2246:7:12",
                    "typeDescriptions": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    }
                  },
                  "value": null,
                  "visibility": "internal"
                }
              ],
              "src": "2245:9:12"
            },
            "scope": 2752,
            "src": "2188:459:12",
            "stateMutability": "pure",
            "virtual": false,
            "visibility": "internal"
          },
          {
            "body": {
              "id": 2681,
              "nodeType": "Block",
              "src": "3176:63:12",
              "statements": [
                {
                  "expression": {
                    "argumentTypes": null,
                    "arguments": [
                      {
                        "argumentTypes": null,
                        "id": 2676,
                        "name": "a",
                        "nodeType": "Identifier",
                        "overloadedDeclarations": [],
                        "referencedDeclaration": 2668,
                        "src": "3197:1:12",
                        "typeDescriptions": {
                          "typeIdentifier": "t_uint256",
                          "typeString": "uint256"
                        }
                      },
                      {
                        "argumentTypes": null,
                        "id": 2677,
                        "name": "b",
                        "nodeType": "Identifier",
                        "overloadedDeclarations": [],
                        "referencedDeclaration": 2670,
                        "src": "3200:1:12",
                        "typeDescriptions": {
                          "typeIdentifier": "t_uint256",
                          "typeString": "uint256"
                        }
                      },
                      {
                        "argumentTypes": null,
                        "hexValue": "536166654d6174683a206469766973696f6e206279207a65726f",
                        "id": 2678,
                        "isConstant": false,
                        "isLValue": false,
                        "isPure": true,
                        "kind": "string",
                        "lValueRequested": false,
                        "nodeType": "Literal",
                        "src": "3203:28:12",
                        "subdenomination": null,
                        "typeDescriptions": {
                          "typeIdentifier": "t_stringliteral_5b7cc70dda4dc2143e5adb63bd5d1f349504f461dbdfd9bc76fac1f8ca6d019f",
                          "typeString": "literal_string \"SafeMath: division by zero\""
                        },
                        "value": "SafeMath: division by zero"
                      }
                    ],
                    "expression": {
                      "argumentTypes": [
                        {
                          "typeIdentifier": "t_uint256",
                          "typeString": "uint256"
                        },
                        {
                          "typeIdentifier": "t_uint256",
                          "typeString": "uint256"
                        },
                        {
                          "typeIdentifier": "t_stringliteral_5b7cc70dda4dc2143e5adb63bd5d1f349504f461dbdfd9bc76fac1f8ca6d019f",
                          "typeString": "literal_string \"SafeMath: division by zero\""
                        }
                      ],
                      "id": 2675,
                      "name": "div",
                      "nodeType": "Identifier",
                      "overloadedDeclarations": [
                        2682,
                        2710
                      ],
                      "referencedDeclaration": 2710,
                      "src": "3193:3:12",
                      "typeDescriptions": {
                        "typeIdentifier": "t_function_internal_pure$_t_uint256_$_t_uint256_$_t_string_memory_ptr_$returns$_t_uint256_$",
                        "typeString": "function (uint256,uint256,string memory) pure returns (uint256)"
                      }
                    },
                    "id": 2679,
                    "isConstant": false,
                    "isLValue": false,
                    "isPure": false,
                    "kind": "functionCall",
                    "lValueRequested": false,
                    "names": [],
                    "nodeType": "FunctionCall",
                    "src": "3193:39:12",
                    "tryCall": false,
                    "typeDescriptions": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    }
                  },
                  "functionReturnParameters": 2674,
                  "id": 2680,
                  "nodeType": "Return",
                  "src": "3186:46:12"
                }
              ]
            },
            "documentation": {
              "id": 2666,
              "nodeType": "StructuredDocumentation",
              "src": "2653:451:12",
              "text": " @dev Returns the integer division of two unsigned integers. Reverts on\n division by zero. The result is rounded towards zero.\n Counterpart to Solidity's `/` operator. Note: this function uses a\n `revert` opcode (which leaves remaining gas untouched) while Solidity\n uses an invalid opcode to revert (consuming all remaining gas).\n Requirements:\n - The divisor cannot be zero."
            },
            "id": 2682,
            "implemented": true,
            "kind": "function",
            "modifiers": [],
            "name": "div",
            "nodeType": "FunctionDefinition",
            "overrides": null,
            "parameters": {
              "id": 2671,
              "nodeType": "ParameterList",
              "parameters": [
                {
                  "constant": false,
                  "id": 2668,
                  "mutability": "mutable",
                  "name": "a",
                  "nodeType": "VariableDeclaration",
                  "overrides": null,
                  "scope": 2682,
                  "src": "3122:9:12",
                  "stateVariable": false,
                  "storageLocation": "default",
                  "typeDescriptions": {
                    "typeIdentifier": "t_uint256",
                    "typeString": "uint256"
                  },
                  "typeName": {
                    "id": 2667,
                    "name": "uint256",
                    "nodeType": "ElementaryTypeName",
                    "src": "3122:7:12",
                    "typeDescriptions": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    }
                  },
                  "value": null,
                  "visibility": "internal"
                },
                {
                  "constant": false,
                  "id": 2670,
                  "mutability": "mutable",
                  "name": "b",
                  "nodeType": "VariableDeclaration",
                  "overrides": null,
                  "scope": 2682,
                  "src": "3133:9:12",
                  "stateVariable": false,
                  "storageLocation": "default",
                  "typeDescriptions": {
                    "typeIdentifier": "t_uint256",
                    "typeString": "uint256"
                  },
                  "typeName": {
                    "id": 2669,
                    "name": "uint256",
                    "nodeType": "ElementaryTypeName",
                    "src": "3133:7:12",
                    "typeDescriptions": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    }
                  },
                  "value": null,
                  "visibility": "internal"
                }
              ],
              "src": "3121:22:12"
            },
            "returnParameters": {
              "id": 2674,
              "nodeType": "ParameterList",
              "parameters": [
                {
                  "constant": false,
                  "id": 2673,
                  "mutability": "mutable",
                  "name": "",
                  "nodeType": "VariableDeclaration",
                  "overrides": null,
                  "scope": 2682,
                  "src": "3167:7:12",
                  "stateVariable": false,
                  "storageLocation": "default",
                  "typeDescriptions": {
                    "typeIdentifier": "t_uint256",
                    "typeString": "uint256"
                  },
                  "typeName": {
                    "id": 2672,
                    "name": "uint256",
                    "nodeType": "ElementaryTypeName",
                    "src": "3167:7:12",
                    "typeDescriptions": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    }
                  },
                  "value": null,
                  "visibility": "internal"
                }
              ],
              "src": "3166:9:12"
            },
            "scope": 2752,
            "src": "3109:130:12",
            "stateMutability": "pure",
            "virtual": false,
            "visibility": "internal"
          },
          {
            "body": {
              "id": 2709,
              "nodeType": "Block",
              "src": "3816:177:12",
              "statements": [
                {
                  "expression": {
                    "argumentTypes": null,
                    "arguments": [
                      {
                        "argumentTypes": null,
                        "commonType": {
                          "typeIdentifier": "t_uint256",
                          "typeString": "uint256"
                        },
                        "id": 2697,
                        "isConstant": false,
                        "isLValue": false,
                        "isPure": false,
                        "lValueRequested": false,
                        "leftExpression": {
                          "argumentTypes": null,
                          "id": 2695,
                          "name": "b",
                          "nodeType": "Identifier",
                          "overloadedDeclarations": [],
                          "referencedDeclaration": 2687,
                          "src": "3834:1:12",
                          "typeDescriptions": {
                            "typeIdentifier": "t_uint256",
                            "typeString": "uint256"
                          }
                        },
                        "nodeType": "BinaryOperation",
                        "operator": ">",
                        "rightExpression": {
                          "argumentTypes": null,
                          "hexValue": "30",
                          "id": 2696,
                          "isConstant": false,
                          "isLValue": false,
                          "isPure": true,
                          "kind": "number",
                          "lValueRequested": false,
                          "nodeType": "Literal",
                          "src": "3838:1:12",
                          "subdenomination": null,
                          "typeDescriptions": {
                            "typeIdentifier": "t_rational_0_by_1",
                            "typeString": "int_const 0"
                          },
                          "value": "0"
                        },
                        "src": "3834:5:12",
                        "typeDescriptions": {
                          "typeIdentifier": "t_bool",
                          "typeString": "bool"
                        }
                      },
                      {
                        "argumentTypes": null,
                        "id": 2698,
                        "name": "errorMessage",
                        "nodeType": "Identifier",
                        "overloadedDeclarations": [],
                        "referencedDeclaration": 2689,
                        "src": "3841:12:12",
                        "typeDescriptions": {
                          "typeIdentifier": "t_string_memory_ptr",
                          "typeString": "string memory"
                        }
                      }
                    ],
                    "expression": {
                      "argumentTypes": [
                        {
                          "typeIdentifier": "t_bool",
                          "typeString": "bool"
                        },
                        {
                          "typeIdentifier": "t_string_memory_ptr",
                          "typeString": "string memory"
                        }
                      ],
                      "id": 2694,
                      "name": "require",
                      "nodeType": "Identifier",
                      "overloadedDeclarations": [
                        -18,
                        -18
                      ],
                      "referencedDeclaration": -18,
                      "src": "3826:7:12",
                      "typeDescriptions": {
                        "typeIdentifier": "t_function_require_pure$_t_bool_$_t_string_memory_ptr_$returns$__$",
                        "typeString": "function (bool,string memory) pure"
                      }
                    },
                    "id": 2699,
                    "isConstant": false,
                    "isLValue": false,
                    "isPure": false,
                    "kind": "functionCall",
                    "lValueRequested": false,
                    "names": [],
                    "nodeType": "FunctionCall",
                    "src": "3826:28:12",
                    "tryCall": false,
                    "typeDescriptions": {
                      "typeIdentifier": "t_tuple$__$",
                      "typeString": "tuple()"
                    }
                  },
                  "id": 2700,
                  "nodeType": "ExpressionStatement",
                  "src": "3826:28:12"
                },
                {
                  "assignments": [
                    2702
                  ],
                  "declarations": [
                    {
                      "constant": false,
                      "id": 2702,
                      "mutability": "mutable",
                      "name": "c",
                      "nodeType": "VariableDeclaration",
                      "overrides": null,
                      "scope": 2709,
                      "src": "3864:9:12",
                      "stateVariable": false,
                      "storageLocation": "default",
                      "typeDescriptions": {
                        "typeIdentifier": "t_uint256",
                        "typeString": "uint256"
                      },
                      "typeName": {
                        "id": 2701,
                        "name": "uint256",
                        "nodeType": "ElementaryTypeName",
                        "src": "3864:7:12",
                        "typeDescriptions": {
                          "typeIdentifier": "t_uint256",
                          "typeString": "uint256"
                        }
                      },
                      "value": null,
                      "visibility": "internal"
                    }
                  ],
                  "id": 2706,
                  "initialValue": {
                    "argumentTypes": null,
                    "commonType": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    },
                    "id": 2705,
                    "isConstant": false,
                    "isLValue": false,
                    "isPure": false,
                    "lValueRequested": false,
                    "leftExpression": {
                      "argumentTypes": null,
                      "id": 2703,
                      "name": "a",
                      "nodeType": "Identifier",
                      "overloadedDeclarations": [],
                      "referencedDeclaration": 2685,
                      "src": "3876:1:12",
                      "typeDescriptions": {
                        "typeIdentifier": "t_uint256",
                        "typeString": "uint256"
                      }
                    },
                    "nodeType": "BinaryOperation",
                    "operator": "/",
                    "rightExpression": {
                      "argumentTypes": null,
                      "id": 2704,
                      "name": "b",
                      "nodeType": "Identifier",
                      "overloadedDeclarations": [],
                      "referencedDeclaration": 2687,
                      "src": "3880:1:12",
                      "typeDescriptions": {
                        "typeIdentifier": "t_uint256",
                        "typeString": "uint256"
                      }
                    },
                    "src": "3876:5:12",
                    "typeDescriptions": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    }
                  },
                  "nodeType": "VariableDeclarationStatement",
                  "src": "3864:17:12"
                },
                {
                  "expression": {
                    "argumentTypes": null,
                    "id": 2707,
                    "name": "c",
                    "nodeType": "Identifier",
                    "overloadedDeclarations": [],
                    "referencedDeclaration": 2702,
                    "src": "3985:1:12",
                    "typeDescriptions": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    }
                  },
                  "functionReturnParameters": 2693,
                  "id": 2708,
                  "nodeType": "Return",
                  "src": "3978:8:12"
                }
              ]
            },
            "documentation": {
              "id": 2683,
              "nodeType": "StructuredDocumentation",
              "src": "3245:471:12",
              "text": " @dev Returns the integer division of two unsigned integers. Reverts with custom message on\n division by zero. The result is rounded towards zero.\n Counterpart to Solidity's `/` operator. Note: this function uses a\n `revert` opcode (which leaves remaining gas untouched) while Solidity\n uses an invalid opcode to revert (consuming all remaining gas).\n Requirements:\n - The divisor cannot be zero."
            },
            "id": 2710,
            "implemented": true,
            "kind": "function",
            "modifiers": [],
            "name": "div",
            "nodeType": "FunctionDefinition",
            "overrides": null,
            "parameters": {
              "id": 2690,
              "nodeType": "ParameterList",
              "parameters": [
                {
                  "constant": false,
                  "id": 2685,
                  "mutability": "mutable",
                  "name": "a",
                  "nodeType": "VariableDeclaration",
                  "overrides": null,
                  "scope": 2710,
                  "src": "3734:9:12",
                  "stateVariable": false,
                  "storageLocation": "default",
                  "typeDescriptions": {
                    "typeIdentifier": "t_uint256",
                    "typeString": "uint256"
                  },
                  "typeName": {
                    "id": 2684,
                    "name": "uint256",
                    "nodeType": "ElementaryTypeName",
                    "src": "3734:7:12",
                    "typeDescriptions": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    }
                  },
                  "value": null,
                  "visibility": "internal"
                },
                {
                  "constant": false,
                  "id": 2687,
                  "mutability": "mutable",
                  "name": "b",
                  "nodeType": "VariableDeclaration",
                  "overrides": null,
                  "scope": 2710,
                  "src": "3745:9:12",
                  "stateVariable": false,
                  "storageLocation": "default",
                  "typeDescriptions": {
                    "typeIdentifier": "t_uint256",
                    "typeString": "uint256"
                  },
                  "typeName": {
                    "id": 2686,
                    "name": "uint256",
                    "nodeType": "ElementaryTypeName",
                    "src": "3745:7:12",
                    "typeDescriptions": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    }
                  },
                  "value": null,
                  "visibility": "internal"
                },
                {
                  "constant": false,
                  "id": 2689,
                  "mutability": "mutable",
                  "name": "errorMessage",
                  "nodeType": "VariableDeclaration",
                  "overrides": null,
                  "scope": 2710,
                  "src": "3756:26:12",
                  "stateVariable": false,
                  "storageLocation": "memory",
                  "typeDescriptions": {
                    "typeIdentifier": "t_string_memory_ptr",
                    "typeString": "string"
                  },
                  "typeName": {
                    "id": 2688,
                    "name": "string",
                    "nodeType": "ElementaryTypeName",
                    "src": "3756:6:12",
                    "typeDescriptions": {
                      "typeIdentifier": "t_string_storage_ptr",
                      "typeString": "string"
                    }
                  },
                  "value": null,
                  "visibility": "internal"
                }
              ],
              "src": "3733:50:12"
            },
            "returnParameters": {
              "id": 2693,
              "nodeType": "ParameterList",
              "parameters": [
                {
                  "constant": false,
                  "id": 2692,
                  "mutability": "mutable",
                  "name": "",
                  "nodeType": "VariableDeclaration",
                  "overrides": null,
                  "scope": 2710,
                  "src": "3807:7:12",
                  "stateVariable": false,
                  "storageLocation": "default",
                  "typeDescriptions": {
                    "typeIdentifier": "t_uint256",
                    "typeString": "uint256"
                  },
                  "typeName": {
                    "id": 2691,
                    "name": "uint256",
                    "nodeType": "ElementaryTypeName",
                    "src": "3807:7:12",
                    "typeDescriptions": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    }
                  },
                  "value": null,
                  "visibility": "internal"
                }
              ],
              "src": "3806:9:12"
            },
            "scope": 2752,
            "src": "3721:272:12",
            "stateMutability": "pure",
            "virtual": false,
            "visibility": "internal"
          },
          {
            "body": {
              "id": 2726,
              "nodeType": "Block",
              "src": "4511:61:12",
              "statements": [
                {
                  "expression": {
                    "argumentTypes": null,
                    "arguments": [
                      {
                        "argumentTypes": null,
                        "id": 2721,
                        "name": "a",
                        "nodeType": "Identifier",
                        "overloadedDeclarations": [],
                        "referencedDeclaration": 2713,
                        "src": "4532:1:12",
                        "typeDescriptions": {
                          "typeIdentifier": "t_uint256",
                          "typeString": "uint256"
                        }
                      },
                      {
                        "argumentTypes": null,
                        "id": 2722,
                        "name": "b",
                        "nodeType": "Identifier",
                        "overloadedDeclarations": [],
                        "referencedDeclaration": 2715,
                        "src": "4535:1:12",
                        "typeDescriptions": {
                          "typeIdentifier": "t_uint256",
                          "typeString": "uint256"
                        }
                      },
                      {
                        "argumentTypes": null,
                        "hexValue": "536166654d6174683a206d6f64756c6f206279207a65726f",
                        "id": 2723,
                        "isConstant": false,
                        "isLValue": false,
                        "isPure": true,
                        "kind": "string",
                        "lValueRequested": false,
                        "nodeType": "Literal",
                        "src": "4538:26:12",
                        "subdenomination": null,
                        "typeDescriptions": {
                          "typeIdentifier": "t_stringliteral_726e51f7b81fce0a68f5f214f445e275313b20b1633f08ce954ee39abf8d7832",
                          "typeString": "literal_string \"SafeMath: modulo by zero\""
                        },
                        "value": "SafeMath: modulo by zero"
                      }
                    ],
                    "expression": {
                      "argumentTypes": [
                        {
                          "typeIdentifier": "t_uint256",
                          "typeString": "uint256"
                        },
                        {
                          "typeIdentifier": "t_uint256",
                          "typeString": "uint256"
                        },
                        {
                          "typeIdentifier": "t_stringliteral_726e51f7b81fce0a68f5f214f445e275313b20b1633f08ce954ee39abf8d7832",
                          "typeString": "literal_string \"SafeMath: modulo by zero\""
                        }
                      ],
                      "id": 2720,
                      "name": "mod",
                      "nodeType": "Identifier",
                      "overloadedDeclarations": [
                        2727,
                        2751
                      ],
                      "referencedDeclaration": 2751,
                      "src": "4528:3:12",
                      "typeDescriptions": {
                        "typeIdentifier": "t_function_internal_pure$_t_uint256_$_t_uint256_$_t_string_memory_ptr_$returns$_t_uint256_$",
                        "typeString": "function (uint256,uint256,string memory) pure returns (uint256)"
                      }
                    },
                    "id": 2724,
                    "isConstant": false,
                    "isLValue": false,
                    "isPure": false,
                    "kind": "functionCall",
                    "lValueRequested": false,
                    "names": [],
                    "nodeType": "FunctionCall",
                    "src": "4528:37:12",
                    "tryCall": false,
                    "typeDescriptions": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    }
                  },
                  "functionReturnParameters": 2719,
                  "id": 2725,
                  "nodeType": "Return",
                  "src": "4521:44:12"
                }
              ]
            },
            "documentation": {
              "id": 2711,
              "nodeType": "StructuredDocumentation",
              "src": "3999:440:12",
              "text": " @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),\n Reverts when dividing by zero.\n Counterpart to Solidity's `%` operator. This function uses a `revert`\n opcode (which leaves remaining gas untouched) while Solidity uses an\n invalid opcode to revert (consuming all remaining gas).\n Requirements:\n - The divisor cannot be zero."
            },
            "id": 2727,
            "implemented": true,
            "kind": "function",
            "modifiers": [],
            "name": "mod",
            "nodeType": "FunctionDefinition",
            "overrides": null,
            "parameters": {
              "id": 2716,
              "nodeType": "ParameterList",
              "parameters": [
                {
                  "constant": false,
                  "id": 2713,
                  "mutability": "mutable",
                  "name": "a",
                  "nodeType": "VariableDeclaration",
                  "overrides": null,
                  "scope": 2727,
                  "src": "4457:9:12",
                  "stateVariable": false,
                  "storageLocation": "default",
                  "typeDescriptions": {
                    "typeIdentifier": "t_uint256",
                    "typeString": "uint256"
                  },
                  "typeName": {
                    "id": 2712,
                    "name": "uint256",
                    "nodeType": "ElementaryTypeName",
                    "src": "4457:7:12",
                    "typeDescriptions": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    }
                  },
                  "value": null,
                  "visibility": "internal"
                },
                {
                  "constant": false,
                  "id": 2715,
                  "mutability": "mutable",
                  "name": "b",
                  "nodeType": "VariableDeclaration",
                  "overrides": null,
                  "scope": 2727,
                  "src": "4468:9:12",
                  "stateVariable": false,
                  "storageLocation": "default",
                  "typeDescriptions": {
                    "typeIdentifier": "t_uint256",
                    "typeString": "uint256"
                  },
                  "typeName": {
                    "id": 2714,
                    "name": "uint256",
                    "nodeType": "ElementaryTypeName",
                    "src": "4468:7:12",
                    "typeDescriptions": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    }
                  },
                  "value": null,
                  "visibility": "internal"
                }
              ],
              "src": "4456:22:12"
            },
            "returnParameters": {
              "id": 2719,
              "nodeType": "ParameterList",
              "parameters": [
                {
                  "constant": false,
                  "id": 2718,
                  "mutability": "mutable",
                  "name": "",
                  "nodeType": "VariableDeclaration",
                  "overrides": null,
                  "scope": 2727,
                  "src": "4502:7:12",
                  "stateVariable": false,
                  "storageLocation": "default",
                  "typeDescriptions": {
                    "typeIdentifier": "t_uint256",
                    "typeString": "uint256"
                  },
                  "typeName": {
                    "id": 2717,
                    "name": "uint256",
                    "nodeType": "ElementaryTypeName",
                    "src": "4502:7:12",
                    "typeDescriptions": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    }
                  },
                  "value": null,
                  "visibility": "internal"
                }
              ],
              "src": "4501:9:12"
            },
            "scope": 2752,
            "src": "4444:128:12",
            "stateMutability": "pure",
            "virtual": false,
            "visibility": "internal"
          },
          {
            "body": {
              "id": 2750,
              "nodeType": "Block",
              "src": "5138:68:12",
              "statements": [
                {
                  "expression": {
                    "argumentTypes": null,
                    "arguments": [
                      {
                        "argumentTypes": null,
                        "commonType": {
                          "typeIdentifier": "t_uint256",
                          "typeString": "uint256"
                        },
                        "id": 2742,
                        "isConstant": false,
                        "isLValue": false,
                        "isPure": false,
                        "lValueRequested": false,
                        "leftExpression": {
                          "argumentTypes": null,
                          "id": 2740,
                          "name": "b",
                          "nodeType": "Identifier",
                          "overloadedDeclarations": [],
                          "referencedDeclaration": 2732,
                          "src": "5156:1:12",
                          "typeDescriptions": {
                            "typeIdentifier": "t_uint256",
                            "typeString": "uint256"
                          }
                        },
                        "nodeType": "BinaryOperation",
                        "operator": "!=",
                        "rightExpression": {
                          "argumentTypes": null,
                          "hexValue": "30",
                          "id": 2741,
                          "isConstant": false,
                          "isLValue": false,
                          "isPure": true,
                          "kind": "number",
                          "lValueRequested": false,
                          "nodeType": "Literal",
                          "src": "5161:1:12",
                          "subdenomination": null,
                          "typeDescriptions": {
                            "typeIdentifier": "t_rational_0_by_1",
                            "typeString": "int_const 0"
                          },
                          "value": "0"
                        },
                        "src": "5156:6:12",
                        "typeDescriptions": {
                          "typeIdentifier": "t_bool",
                          "typeString": "bool"
                        }
                      },
                      {
                        "argumentTypes": null,
                        "id": 2743,
                        "name": "errorMessage",
                        "nodeType": "Identifier",
                        "overloadedDeclarations": [],
                        "referencedDeclaration": 2734,
                        "src": "5164:12:12",
                        "typeDescriptions": {
                          "typeIdentifier": "t_string_memory_ptr",
                          "typeString": "string memory"
                        }
                      }
                    ],
                    "expression": {
                      "argumentTypes": [
                        {
                          "typeIdentifier": "t_bool",
                          "typeString": "bool"
                        },
                        {
                          "typeIdentifier": "t_string_memory_ptr",
                          "typeString": "string memory"
                        }
                      ],
                      "id": 2739,
                      "name": "require",
                      "nodeType": "Identifier",
                      "overloadedDeclarations": [
                        -18,
                        -18
                      ],
                      "referencedDeclaration": -18,
                      "src": "5148:7:12",
                      "typeDescriptions": {
                        "typeIdentifier": "t_function_require_pure$_t_bool_$_t_string_memory_ptr_$returns$__$",
                        "typeString": "function (bool,string memory) pure"
                      }
                    },
                    "id": 2744,
                    "isConstant": false,
                    "isLValue": false,
                    "isPure": false,
                    "kind": "functionCall",
                    "lValueRequested": false,
                    "names": [],
                    "nodeType": "FunctionCall",
                    "src": "5148:29:12",
                    "tryCall": false,
                    "typeDescriptions": {
                      "typeIdentifier": "t_tuple$__$",
                      "typeString": "tuple()"
                    }
                  },
                  "id": 2745,
                  "nodeType": "ExpressionStatement",
                  "src": "5148:29:12"
                },
                {
                  "expression": {
                    "argumentTypes": null,
                    "commonType": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    },
                    "id": 2748,
                    "isConstant": false,
                    "isLValue": false,
                    "isPure": false,
                    "lValueRequested": false,
                    "leftExpression": {
                      "argumentTypes": null,
                      "id": 2746,
                      "name": "a",
                      "nodeType": "Identifier",
                      "overloadedDeclarations": [],
                      "referencedDeclaration": 2730,
                      "src": "5194:1:12",
                      "typeDescriptions": {
                        "typeIdentifier": "t_uint256",
                        "typeString": "uint256"
                      }
                    },
                    "nodeType": "BinaryOperation",
                    "operator": "%",
                    "rightExpression": {
                      "argumentTypes": null,
                      "id": 2747,
                      "name": "b",
                      "nodeType": "Identifier",
                      "overloadedDeclarations": [],
                      "referencedDeclaration": 2732,
                      "src": "5198:1:12",
                      "typeDescriptions": {
                        "typeIdentifier": "t_uint256",
                        "typeString": "uint256"
                      }
                    },
                    "src": "5194:5:12",
                    "typeDescriptions": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    }
                  },
                  "functionReturnParameters": 2738,
                  "id": 2749,
                  "nodeType": "Return",
                  "src": "5187:12:12"
                }
              ]
            },
            "documentation": {
              "id": 2728,
              "nodeType": "StructuredDocumentation",
              "src": "4578:460:12",
              "text": " @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),\n Reverts with custom message when dividing by zero.\n Counterpart to Solidity's `%` operator. This function uses a `revert`\n opcode (which leaves remaining gas untouched) while Solidity uses an\n invalid opcode to revert (consuming all remaining gas).\n Requirements:\n - The divisor cannot be zero."
            },
            "id": 2751,
            "implemented": true,
            "kind": "function",
            "modifiers": [],
            "name": "mod",
            "nodeType": "FunctionDefinition",
            "overrides": null,
            "parameters": {
              "id": 2735,
              "nodeType": "ParameterList",
              "parameters": [
                {
                  "constant": false,
                  "id": 2730,
                  "mutability": "mutable",
                  "name": "a",
                  "nodeType": "VariableDeclaration",
                  "overrides": null,
                  "scope": 2751,
                  "src": "5056:9:12",
                  "stateVariable": false,
                  "storageLocation": "default",
                  "typeDescriptions": {
                    "typeIdentifier": "t_uint256",
                    "typeString": "uint256"
                  },
                  "typeName": {
                    "id": 2729,
                    "name": "uint256",
                    "nodeType": "ElementaryTypeName",
                    "src": "5056:7:12",
                    "typeDescriptions": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    }
                  },
                  "value": null,
                  "visibility": "internal"
                },
                {
                  "constant": false,
                  "id": 2732,
                  "mutability": "mutable",
                  "name": "b",
                  "nodeType": "VariableDeclaration",
                  "overrides": null,
                  "scope": 2751,
                  "src": "5067:9:12",
                  "stateVariable": false,
                  "storageLocation": "default",
                  "typeDescriptions": {
                    "typeIdentifier": "t_uint256",
                    "typeString": "uint256"
                  },
                  "typeName": {
                    "id": 2731,
                    "name": "uint256",
                    "nodeType": "ElementaryTypeName",
                    "src": "5067:7:12",
                    "typeDescriptions": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    }
                  },
                  "value": null,
                  "visibility": "internal"
                },
                {
                  "constant": false,
                  "id": 2734,
                  "mutability": "mutable",
                  "name": "errorMessage",
                  "nodeType": "VariableDeclaration",
                  "overrides": null,
                  "scope": 2751,
                  "src": "5078:26:12",
                  "stateVariable": false,
                  "storageLocation": "memory",
                  "typeDescriptions": {
                    "typeIdentifier": "t_string_memory_ptr",
                    "typeString": "string"
                  },
                  "typeName": {
                    "id": 2733,
                    "name": "string",
                    "nodeType": "ElementaryTypeName",
                    "src": "5078:6:12",
                    "typeDescriptions": {
                      "typeIdentifier": "t_string_storage_ptr",
                      "typeString": "string"
                    }
                  },
                  "value": null,
                  "visibility": "internal"
                }
              ],
              "src": "5055:50:12"
            },
            "returnParameters": {
              "id": 2738,
              "nodeType": "ParameterList",
              "parameters": [
                {
                  "constant": false,
                  "id": 2737,
                  "mutability": "mutable",
                  "name": "",
                  "nodeType": "VariableDeclaration",
                  "overrides": null,
                  "scope": 2751,
                  "src": "5129:7:12",
                  "stateVariable": false,
                  "storageLocation": "default",
                  "typeDescriptions": {
                    "typeIdentifier": "t_uint256",
                    "typeString": "uint256"
                  },
                  "typeName": {
                    "id": 2736,
                    "name": "uint256",
                    "nodeType": "ElementaryTypeName",
                    "src": "5129:7:12",
                    "typeDescriptions": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    }
                  },
                  "value": null,
                  "visibility": "internal"
                }
              ],
              "src": "5128:9:12"
            },
            "scope": 2752,
            "src": "5043:163:12",
            "stateMutability": "pure",
            "virtual": false,
            "visibility": "internal"
          }
        ],
        "scope": 2753,
        "src": "630:4578:12"
      }
    ],
    "src": "33:5176:12"
  },
  "legacyAST": {
    "absolutePath": "@openzeppelin/contracts/math/SafeMath.sol",
    "exportedSymbols": {
      "SafeMath": [
        2752
      ]
    },
    "id": 2753,
    "license": "MIT",
    "nodeType": "SourceUnit",
    "nodes": [
      {
        "id": 2558,
        "literals": [
          "solidity",
          ">=",
          "0.6",
          ".0",
          "<",
          "0.8",
          ".0"
        ],
        "nodeType": "PragmaDirective",
        "src": "33:31:12"
      },
      {
        "abstract": false,
        "baseContracts": [],
        "contractDependencies": [],
        "contractKind": "library",
        "documentation": {
          "id": 2559,
          "nodeType": "StructuredDocumentation",
          "src": "66:563:12",
          "text": " @dev Wrappers over Solidity's arithmetic operations with added overflow\n checks.\n Arithmetic operations in Solidity wrap on overflow. This can easily result\n in bugs, because programmers usually assume that an overflow raises an\n error, which is the standard behavior in high level programming languages.\n `SafeMath` restores this intuition by reverting the transaction when an\n operation overflows.\n Using this library instead of the unchecked operations eliminates an entire\n class of bugs, so it's recommended to use it always."
        },
        "fullyImplemented": true,
        "id": 2752,
        "linearizedBaseContracts": [
          2752
        ],
        "name": "SafeMath",
        "nodeType": "ContractDefinition",
        "nodes": [
          {
            "body": {
              "id": 2584,
              "nodeType": "Block",
              "src": "949:109:12",
              "statements": [
                {
                  "assignments": [
                    2570
                  ],
                  "declarations": [
                    {
                      "constant": false,
                      "id": 2570,
                      "mutability": "mutable",
                      "name": "c",
                      "nodeType": "VariableDeclaration",
                      "overrides": null,
                      "scope": 2584,
                      "src": "959:9:12",
                      "stateVariable": false,
                      "storageLocation": "default",
                      "typeDescriptions": {
                        "typeIdentifier": "t_uint256",
                        "typeString": "uint256"
                      },
                      "typeName": {
                        "id": 2569,
                        "name": "uint256",
                        "nodeType": "ElementaryTypeName",
                        "src": "959:7:12",
                        "typeDescriptions": {
                          "typeIdentifier": "t_uint256",
                          "typeString": "uint256"
                        }
                      },
                      "value": null,
                      "visibility": "internal"
                    }
                  ],
                  "id": 2574,
                  "initialValue": {
                    "argumentTypes": null,
                    "commonType": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    },
                    "id": 2573,
                    "isConstant": false,
                    "isLValue": false,
                    "isPure": false,
                    "lValueRequested": false,
                    "leftExpression": {
                      "argumentTypes": null,
                      "id": 2571,
                      "name": "a",
                      "nodeType": "Identifier",
                      "overloadedDeclarations": [],
                      "referencedDeclaration": 2562,
                      "src": "971:1:12",
                      "typeDescriptions": {
                        "typeIdentifier": "t_uint256",
                        "typeString": "uint256"
                      }
                    },
                    "nodeType": "BinaryOperation",
                    "operator": "+",
                    "rightExpression": {
                      "argumentTypes": null,
                      "id": 2572,
                      "name": "b",
                      "nodeType": "Identifier",
                      "overloadedDeclarations": [],
                      "referencedDeclaration": 2564,
                      "src": "975:1:12",
                      "typeDescriptions": {
                        "typeIdentifier": "t_uint256",
                        "typeString": "uint256"
                      }
                    },
                    "src": "971:5:12",
                    "typeDescriptions": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    }
                  },
                  "nodeType": "VariableDeclarationStatement",
                  "src": "959:17:12"
                },
                {
                  "expression": {
                    "argumentTypes": null,
                    "arguments": [
                      {
                        "argumentTypes": null,
                        "commonType": {
                          "typeIdentifier": "t_uint256",
                          "typeString": "uint256"
                        },
                        "id": 2578,
                        "isConstant": false,
                        "isLValue": false,
                        "isPure": false,
                        "lValueRequested": false,
                        "leftExpression": {
                          "argumentTypes": null,
                          "id": 2576,
                          "name": "c",
                          "nodeType": "Identifier",
                          "overloadedDeclarations": [],
                          "referencedDeclaration": 2570,
                          "src": "994:1:12",
                          "typeDescriptions": {
                            "typeIdentifier": "t_uint256",
                            "typeString": "uint256"
                          }
                        },
                        "nodeType": "BinaryOperation",
                        "operator": ">=",
                        "rightExpression": {
                          "argumentTypes": null,
                          "id": 2577,
                          "name": "a",
                          "nodeType": "Identifier",
                          "overloadedDeclarations": [],
                          "referencedDeclaration": 2562,
                          "src": "999:1:12",
                          "typeDescriptions": {
                            "typeIdentifier": "t_uint256",
                            "typeString": "uint256"
                          }
                        },
                        "src": "994:6:12",
                        "typeDescriptions": {
                          "typeIdentifier": "t_bool",
                          "typeString": "bool"
                        }
                      },
                      {
                        "argumentTypes": null,
                        "hexValue": "536166654d6174683a206164646974696f6e206f766572666c6f77",
                        "id": 2579,
                        "isConstant": false,
                        "isLValue": false,
                        "isPure": true,
                        "kind": "string",
                        "lValueRequested": false,
                        "nodeType": "Literal",
                        "src": "1002:29:12",
                        "subdenomination": null,
                        "typeDescriptions": {
                          "typeIdentifier": "t_stringliteral_30cc447bcc13b3e22b45cef0dd9b0b514842d836dd9b6eb384e20dedfb47723a",
                          "typeString": "literal_string \"SafeMath: addition overflow\""
                        },
                        "value": "SafeMath: addition overflow"
                      }
                    ],
                    "expression": {
                      "argumentTypes": [
                        {
                          "typeIdentifier": "t_bool",
                          "typeString": "bool"
                        },
                        {
                          "typeIdentifier": "t_stringliteral_30cc447bcc13b3e22b45cef0dd9b0b514842d836dd9b6eb384e20dedfb47723a",
                          "typeString": "literal_string \"SafeMath: addition overflow\""
                        }
                      ],
                      "id": 2575,
                      "name": "require",
                      "nodeType": "Identifier",
                      "overloadedDeclarations": [
                        -18,
                        -18
                      ],
                      "referencedDeclaration": -18,
                      "src": "986:7:12",
                      "typeDescriptions": {
                        "typeIdentifier": "t_function_require_pure$_t_bool_$_t_string_memory_ptr_$returns$__$",
                        "typeString": "function (bool,string memory) pure"
                      }
                    },
                    "id": 2580,
                    "isConstant": false,
                    "isLValue": false,
                    "isPure": false,
                    "kind": "functionCall",
                    "lValueRequested": false,
                    "names": [],
                    "nodeType": "FunctionCall",
                    "src": "986:46:12",
                    "tryCall": false,
                    "typeDescriptions": {
                      "typeIdentifier": "t_tuple$__$",
                      "typeString": "tuple()"
                    }
                  },
                  "id": 2581,
                  "nodeType": "ExpressionStatement",
                  "src": "986:46:12"
                },
                {
                  "expression": {
                    "argumentTypes": null,
                    "id": 2582,
                    "name": "c",
                    "nodeType": "Identifier",
                    "overloadedDeclarations": [],
                    "referencedDeclaration": 2570,
                    "src": "1050:1:12",
                    "typeDescriptions": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    }
                  },
                  "functionReturnParameters": 2568,
                  "id": 2583,
                  "nodeType": "Return",
                  "src": "1043:8:12"
                }
              ]
            },
            "documentation": {
              "id": 2560,
              "nodeType": "StructuredDocumentation",
              "src": "653:224:12",
              "text": " @dev Returns the addition of two unsigned integers, reverting on\n overflow.\n Counterpart to Solidity's `+` operator.\n Requirements:\n - Addition cannot overflow."
            },
            "id": 2585,
            "implemented": true,
            "kind": "function",
            "modifiers": [],
            "name": "add",
            "nodeType": "FunctionDefinition",
            "overrides": null,
            "parameters": {
              "id": 2565,
              "nodeType": "ParameterList",
              "parameters": [
                {
                  "constant": false,
                  "id": 2562,
                  "mutability": "mutable",
                  "name": "a",
                  "nodeType": "VariableDeclaration",
                  "overrides": null,
                  "scope": 2585,
                  "src": "895:9:12",
                  "stateVariable": false,
                  "storageLocation": "default",
                  "typeDescriptions": {
                    "typeIdentifier": "t_uint256",
                    "typeString": "uint256"
                  },
                  "typeName": {
                    "id": 2561,
                    "name": "uint256",
                    "nodeType": "ElementaryTypeName",
                    "src": "895:7:12",
                    "typeDescriptions": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    }
                  },
                  "value": null,
                  "visibility": "internal"
                },
                {
                  "constant": false,
                  "id": 2564,
                  "mutability": "mutable",
                  "name": "b",
                  "nodeType": "VariableDeclaration",
                  "overrides": null,
                  "scope": 2585,
                  "src": "906:9:12",
                  "stateVariable": false,
                  "storageLocation": "default",
                  "typeDescriptions": {
                    "typeIdentifier": "t_uint256",
                    "typeString": "uint256"
                  },
                  "typeName": {
                    "id": 2563,
                    "name": "uint256",
                    "nodeType": "ElementaryTypeName",
                    "src": "906:7:12",
                    "typeDescriptions": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    }
                  },
                  "value": null,
                  "visibility": "internal"
                }
              ],
              "src": "894:22:12"
            },
            "returnParameters": {
              "id": 2568,
              "nodeType": "ParameterList",
              "parameters": [
                {
                  "constant": false,
                  "id": 2567,
                  "mutability": "mutable",
                  "name": "",
                  "nodeType": "VariableDeclaration",
                  "overrides": null,
                  "scope": 2585,
                  "src": "940:7:12",
                  "stateVariable": false,
                  "storageLocation": "default",
                  "typeDescriptions": {
                    "typeIdentifier": "t_uint256",
                    "typeString": "uint256"
                  },
                  "typeName": {
                    "id": 2566,
                    "name": "uint256",
                    "nodeType": "ElementaryTypeName",
                    "src": "940:7:12",
                    "typeDescriptions": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    }
                  },
                  "value": null,
                  "visibility": "internal"
                }
              ],
              "src": "939:9:12"
            },
            "scope": 2752,
            "src": "882:176:12",
            "stateMutability": "pure",
            "virtual": false,
            "visibility": "internal"
          },
          {
            "body": {
              "id": 2601,
              "nodeType": "Block",
              "src": "1396:67:12",
              "statements": [
                {
                  "expression": {
                    "argumentTypes": null,
                    "arguments": [
                      {
                        "argumentTypes": null,
                        "id": 2596,
                        "name": "a",
                        "nodeType": "Identifier",
                        "overloadedDeclarations": [],
                        "referencedDeclaration": 2588,
                        "src": "1417:1:12",
                        "typeDescriptions": {
                          "typeIdentifier": "t_uint256",
                          "typeString": "uint256"
                        }
                      },
                      {
                        "argumentTypes": null,
                        "id": 2597,
                        "name": "b",
                        "nodeType": "Identifier",
                        "overloadedDeclarations": [],
                        "referencedDeclaration": 2590,
                        "src": "1420:1:12",
                        "typeDescriptions": {
                          "typeIdentifier": "t_uint256",
                          "typeString": "uint256"
                        }
                      },
                      {
                        "argumentTypes": null,
                        "hexValue": "536166654d6174683a207375627472616374696f6e206f766572666c6f77",
                        "id": 2598,
                        "isConstant": false,
                        "isLValue": false,
                        "isPure": true,
                        "kind": "string",
                        "lValueRequested": false,
                        "nodeType": "Literal",
                        "src": "1423:32:12",
                        "subdenomination": null,
                        "typeDescriptions": {
                          "typeIdentifier": "t_stringliteral_50b058e9b5320e58880d88223c9801cd9eecdcf90323d5c2318bc1b6b916e862",
                          "typeString": "literal_string \"SafeMath: subtraction overflow\""
                        },
                        "value": "SafeMath: subtraction overflow"
                      }
                    ],
                    "expression": {
                      "argumentTypes": [
                        {
                          "typeIdentifier": "t_uint256",
                          "typeString": "uint256"
                        },
                        {
                          "typeIdentifier": "t_uint256",
                          "typeString": "uint256"
                        },
                        {
                          "typeIdentifier": "t_stringliteral_50b058e9b5320e58880d88223c9801cd9eecdcf90323d5c2318bc1b6b916e862",
                          "typeString": "literal_string \"SafeMath: subtraction overflow\""
                        }
                      ],
                      "id": 2595,
                      "name": "sub",
                      "nodeType": "Identifier",
                      "overloadedDeclarations": [
                        2602,
                        2630
                      ],
                      "referencedDeclaration": 2630,
                      "src": "1413:3:12",
                      "typeDescriptions": {
                        "typeIdentifier": "t_function_internal_pure$_t_uint256_$_t_uint256_$_t_string_memory_ptr_$returns$_t_uint256_$",
                        "typeString": "function (uint256,uint256,string memory) pure returns (uint256)"
                      }
                    },
                    "id": 2599,
                    "isConstant": false,
                    "isLValue": false,
                    "isPure": false,
                    "kind": "functionCall",
                    "lValueRequested": false,
                    "names": [],
                    "nodeType": "FunctionCall",
                    "src": "1413:43:12",
                    "tryCall": false,
                    "typeDescriptions": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    }
                  },
                  "functionReturnParameters": 2594,
                  "id": 2600,
                  "nodeType": "Return",
                  "src": "1406:50:12"
                }
              ]
            },
            "documentation": {
              "id": 2586,
              "nodeType": "StructuredDocumentation",
              "src": "1064:260:12",
              "text": " @dev Returns the subtraction of two unsigned integers, reverting on\n overflow (when the result is negative).\n Counterpart to Solidity's `-` operator.\n Requirements:\n - Subtraction cannot overflow."
            },
            "id": 2602,
            "implemented": true,
            "kind": "function",
            "modifiers": [],
            "name": "sub",
            "nodeType": "FunctionDefinition",
            "overrides": null,
            "parameters": {
              "id": 2591,
              "nodeType": "ParameterList",
              "parameters": [
                {
                  "constant": false,
                  "id": 2588,
                  "mutability": "mutable",
                  "name": "a",
                  "nodeType": "VariableDeclaration",
                  "overrides": null,
                  "scope": 2602,
                  "src": "1342:9:12",
                  "stateVariable": false,
                  "storageLocation": "default",
                  "typeDescriptions": {
                    "typeIdentifier": "t_uint256",
                    "typeString": "uint256"
                  },
                  "typeName": {
                    "id": 2587,
                    "name": "uint256",
                    "nodeType": "ElementaryTypeName",
                    "src": "1342:7:12",
                    "typeDescriptions": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    }
                  },
                  "value": null,
                  "visibility": "internal"
                },
                {
                  "constant": false,
                  "id": 2590,
                  "mutability": "mutable",
                  "name": "b",
                  "nodeType": "VariableDeclaration",
                  "overrides": null,
                  "scope": 2602,
                  "src": "1353:9:12",
                  "stateVariable": false,
                  "storageLocation": "default",
                  "typeDescriptions": {
                    "typeIdentifier": "t_uint256",
                    "typeString": "uint256"
                  },
                  "typeName": {
                    "id": 2589,
                    "name": "uint256",
                    "nodeType": "ElementaryTypeName",
                    "src": "1353:7:12",
                    "typeDescriptions": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    }
                  },
                  "value": null,
                  "visibility": "internal"
                }
              ],
              "src": "1341:22:12"
            },
            "returnParameters": {
              "id": 2594,
              "nodeType": "ParameterList",
              "parameters": [
                {
                  "constant": false,
                  "id": 2593,
                  "mutability": "mutable",
                  "name": "",
                  "nodeType": "VariableDeclaration",
                  "overrides": null,
                  "scope": 2602,
                  "src": "1387:7:12",
                  "stateVariable": false,
                  "storageLocation": "default",
                  "typeDescriptions": {
                    "typeIdentifier": "t_uint256",
                    "typeString": "uint256"
                  },
                  "typeName": {
                    "id": 2592,
                    "name": "uint256",
                    "nodeType": "ElementaryTypeName",
                    "src": "1387:7:12",
                    "typeDescriptions": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    }
                  },
                  "value": null,
                  "visibility": "internal"
                }
              ],
              "src": "1386:9:12"
            },
            "scope": 2752,
            "src": "1329:134:12",
            "stateMutability": "pure",
            "virtual": false,
            "visibility": "internal"
          },
          {
            "body": {
              "id": 2629,
              "nodeType": "Block",
              "src": "1849:92:12",
              "statements": [
                {
                  "expression": {
                    "argumentTypes": null,
                    "arguments": [
                      {
                        "argumentTypes": null,
                        "commonType": {
                          "typeIdentifier": "t_uint256",
                          "typeString": "uint256"
                        },
                        "id": 2617,
                        "isConstant": false,
                        "isLValue": false,
                        "isPure": false,
                        "lValueRequested": false,
                        "leftExpression": {
                          "argumentTypes": null,
                          "id": 2615,
                          "name": "b",
                          "nodeType": "Identifier",
                          "overloadedDeclarations": [],
                          "referencedDeclaration": 2607,
                          "src": "1867:1:12",
                          "typeDescriptions": {
                            "typeIdentifier": "t_uint256",
                            "typeString": "uint256"
                          }
                        },
                        "nodeType": "BinaryOperation",
                        "operator": "<=",
                        "rightExpression": {
                          "argumentTypes": null,
                          "id": 2616,
                          "name": "a",
                          "nodeType": "Identifier",
                          "overloadedDeclarations": [],
                          "referencedDeclaration": 2605,
                          "src": "1872:1:12",
                          "typeDescriptions": {
                            "typeIdentifier": "t_uint256",
                            "typeString": "uint256"
                          }
                        },
                        "src": "1867:6:12",
                        "typeDescriptions": {
                          "typeIdentifier": "t_bool",
                          "typeString": "bool"
                        }
                      },
                      {
                        "argumentTypes": null,
                        "id": 2618,
                        "name": "errorMessage",
                        "nodeType": "Identifier",
                        "overloadedDeclarations": [],
                        "referencedDeclaration": 2609,
                        "src": "1875:12:12",
                        "typeDescriptions": {
                          "typeIdentifier": "t_string_memory_ptr",
                          "typeString": "string memory"
                        }
                      }
                    ],
                    "expression": {
                      "argumentTypes": [
                        {
                          "typeIdentifier": "t_bool",
                          "typeString": "bool"
                        },
                        {
                          "typeIdentifier": "t_string_memory_ptr",
                          "typeString": "string memory"
                        }
                      ],
                      "id": 2614,
                      "name": "require",
                      "nodeType": "Identifier",
                      "overloadedDeclarations": [
                        -18,
                        -18
                      ],
                      "referencedDeclaration": -18,
                      "src": "1859:7:12",
                      "typeDescriptions": {
                        "typeIdentifier": "t_function_require_pure$_t_bool_$_t_string_memory_ptr_$returns$__$",
                        "typeString": "function (bool,string memory) pure"
                      }
                    },
                    "id": 2619,
                    "isConstant": false,
                    "isLValue": false,
                    "isPure": false,
                    "kind": "functionCall",
                    "lValueRequested": false,
                    "names": [],
                    "nodeType": "FunctionCall",
                    "src": "1859:29:12",
                    "tryCall": false,
                    "typeDescriptions": {
                      "typeIdentifier": "t_tuple$__$",
                      "typeString": "tuple()"
                    }
                  },
                  "id": 2620,
                  "nodeType": "ExpressionStatement",
                  "src": "1859:29:12"
                },
                {
                  "assignments": [
                    2622
                  ],
                  "declarations": [
                    {
                      "constant": false,
                      "id": 2622,
                      "mutability": "mutable",
                      "name": "c",
                      "nodeType": "VariableDeclaration",
                      "overrides": null,
                      "scope": 2629,
                      "src": "1898:9:12",
                      "stateVariable": false,
                      "storageLocation": "default",
                      "typeDescriptions": {
                        "typeIdentifier": "t_uint256",
                        "typeString": "uint256"
                      },
                      "typeName": {
                        "id": 2621,
                        "name": "uint256",
                        "nodeType": "ElementaryTypeName",
                        "src": "1898:7:12",
                        "typeDescriptions": {
                          "typeIdentifier": "t_uint256",
                          "typeString": "uint256"
                        }
                      },
                      "value": null,
                      "visibility": "internal"
                    }
                  ],
                  "id": 2626,
                  "initialValue": {
                    "argumentTypes": null,
                    "commonType": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    },
                    "id": 2625,
                    "isConstant": false,
                    "isLValue": false,
                    "isPure": false,
                    "lValueRequested": false,
                    "leftExpression": {
                      "argumentTypes": null,
                      "id": 2623,
                      "name": "a",
                      "nodeType": "Identifier",
                      "overloadedDeclarations": [],
                      "referencedDeclaration": 2605,
                      "src": "1910:1:12",
                      "typeDescriptions": {
                        "typeIdentifier": "t_uint256",
                        "typeString": "uint256"
                      }
                    },
                    "nodeType": "BinaryOperation",
                    "operator": "-",
                    "rightExpression": {
                      "argumentTypes": null,
                      "id": 2624,
                      "name": "b",
                      "nodeType": "Identifier",
                      "overloadedDeclarations": [],
                      "referencedDeclaration": 2607,
                      "src": "1914:1:12",
                      "typeDescriptions": {
                        "typeIdentifier": "t_uint256",
                        "typeString": "uint256"
                      }
                    },
                    "src": "1910:5:12",
                    "typeDescriptions": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    }
                  },
                  "nodeType": "VariableDeclarationStatement",
                  "src": "1898:17:12"
                },
                {
                  "expression": {
                    "argumentTypes": null,
                    "id": 2627,
                    "name": "c",
                    "nodeType": "Identifier",
                    "overloadedDeclarations": [],
                    "referencedDeclaration": 2622,
                    "src": "1933:1:12",
                    "typeDescriptions": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    }
                  },
                  "functionReturnParameters": 2613,
                  "id": 2628,
                  "nodeType": "Return",
                  "src": "1926:8:12"
                }
              ]
            },
            "documentation": {
              "id": 2603,
              "nodeType": "StructuredDocumentation",
              "src": "1469:280:12",
              "text": " @dev Returns the subtraction of two unsigned integers, reverting with custom message on\n overflow (when the result is negative).\n Counterpart to Solidity's `-` operator.\n Requirements:\n - Subtraction cannot overflow."
            },
            "id": 2630,
            "implemented": true,
            "kind": "function",
            "modifiers": [],
            "name": "sub",
            "nodeType": "FunctionDefinition",
            "overrides": null,
            "parameters": {
              "id": 2610,
              "nodeType": "ParameterList",
              "parameters": [
                {
                  "constant": false,
                  "id": 2605,
                  "mutability": "mutable",
                  "name": "a",
                  "nodeType": "VariableDeclaration",
                  "overrides": null,
                  "scope": 2630,
                  "src": "1767:9:12",
                  "stateVariable": false,
                  "storageLocation": "default",
                  "typeDescriptions": {
                    "typeIdentifier": "t_uint256",
                    "typeString": "uint256"
                  },
                  "typeName": {
                    "id": 2604,
                    "name": "uint256",
                    "nodeType": "ElementaryTypeName",
                    "src": "1767:7:12",
                    "typeDescriptions": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    }
                  },
                  "value": null,
                  "visibility": "internal"
                },
                {
                  "constant": false,
                  "id": 2607,
                  "mutability": "mutable",
                  "name": "b",
                  "nodeType": "VariableDeclaration",
                  "overrides": null,
                  "scope": 2630,
                  "src": "1778:9:12",
                  "stateVariable": false,
                  "storageLocation": "default",
                  "typeDescriptions": {
                    "typeIdentifier": "t_uint256",
                    "typeString": "uint256"
                  },
                  "typeName": {
                    "id": 2606,
                    "name": "uint256",
                    "nodeType": "ElementaryTypeName",
                    "src": "1778:7:12",
                    "typeDescriptions": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    }
                  },
                  "value": null,
                  "visibility": "internal"
                },
                {
                  "constant": false,
                  "id": 2609,
                  "mutability": "mutable",
                  "name": "errorMessage",
                  "nodeType": "VariableDeclaration",
                  "overrides": null,
                  "scope": 2630,
                  "src": "1789:26:12",
                  "stateVariable": false,
                  "storageLocation": "memory",
                  "typeDescriptions": {
                    "typeIdentifier": "t_string_memory_ptr",
                    "typeString": "string"
                  },
                  "typeName": {
                    "id": 2608,
                    "name": "string",
                    "nodeType": "ElementaryTypeName",
                    "src": "1789:6:12",
                    "typeDescriptions": {
                      "typeIdentifier": "t_string_storage_ptr",
                      "typeString": "string"
                    }
                  },
                  "value": null,
                  "visibility": "internal"
                }
              ],
              "src": "1766:50:12"
            },
            "returnParameters": {
              "id": 2613,
              "nodeType": "ParameterList",
              "parameters": [
                {
                  "constant": false,
                  "id": 2612,
                  "mutability": "mutable",
                  "name": "",
                  "nodeType": "VariableDeclaration",
                  "overrides": null,
                  "scope": 2630,
                  "src": "1840:7:12",
                  "stateVariable": false,
                  "storageLocation": "default",
                  "typeDescriptions": {
                    "typeIdentifier": "t_uint256",
                    "typeString": "uint256"
                  },
                  "typeName": {
                    "id": 2611,
                    "name": "uint256",
                    "nodeType": "ElementaryTypeName",
                    "src": "1840:7:12",
                    "typeDescriptions": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    }
                  },
                  "value": null,
                  "visibility": "internal"
                }
              ],
              "src": "1839:9:12"
            },
            "scope": 2752,
            "src": "1754:187:12",
            "stateMutability": "pure",
            "virtual": false,
            "visibility": "internal"
          },
          {
            "body": {
              "id": 2664,
              "nodeType": "Block",
              "src": "2255:392:12",
              "statements": [
                {
                  "condition": {
                    "argumentTypes": null,
                    "commonType": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    },
                    "id": 2642,
                    "isConstant": false,
                    "isLValue": false,
                    "isPure": false,
                    "lValueRequested": false,
                    "leftExpression": {
                      "argumentTypes": null,
                      "id": 2640,
                      "name": "a",
                      "nodeType": "Identifier",
                      "overloadedDeclarations": [],
                      "referencedDeclaration": 2633,
                      "src": "2487:1:12",
                      "typeDescriptions": {
                        "typeIdentifier": "t_uint256",
                        "typeString": "uint256"
                      }
                    },
                    "nodeType": "BinaryOperation",
                    "operator": "==",
                    "rightExpression": {
                      "argumentTypes": null,
                      "hexValue": "30",
                      "id": 2641,
                      "isConstant": false,
                      "isLValue": false,
                      "isPure": true,
                      "kind": "number",
                      "lValueRequested": false,
                      "nodeType": "Literal",
                      "src": "2492:1:12",
                      "subdenomination": null,
                      "typeDescriptions": {
                        "typeIdentifier": "t_rational_0_by_1",
                        "typeString": "int_const 0"
                      },
                      "value": "0"
                    },
                    "src": "2487:6:12",
                    "typeDescriptions": {
                      "typeIdentifier": "t_bool",
                      "typeString": "bool"
                    }
                  },
                  "falseBody": null,
                  "id": 2646,
                  "nodeType": "IfStatement",
                  "src": "2483:45:12",
                  "trueBody": {
                    "id": 2645,
                    "nodeType": "Block",
                    "src": "2495:33:12",
                    "statements": [
                      {
                        "expression": {
                          "argumentTypes": null,
                          "hexValue": "30",
                          "id": 2643,
                          "isConstant": false,
                          "isLValue": false,
                          "isPure": true,
                          "kind": "number",
                          "lValueRequested": false,
                          "nodeType": "Literal",
                          "src": "2516:1:12",
                          "subdenomination": null,
                          "typeDescriptions": {
                            "typeIdentifier": "t_rational_0_by_1",
                            "typeString": "int_const 0"
                          },
                          "value": "0"
                        },
                        "functionReturnParameters": 2639,
                        "id": 2644,
                        "nodeType": "Return",
                        "src": "2509:8:12"
                      }
                    ]
                  }
                },
                {
                  "assignments": [
                    2648
                  ],
                  "declarations": [
                    {
                      "constant": false,
                      "id": 2648,
                      "mutability": "mutable",
                      "name": "c",
                      "nodeType": "VariableDeclaration",
                      "overrides": null,
                      "scope": 2664,
                      "src": "2538:9:12",
                      "stateVariable": false,
                      "storageLocation": "default",
                      "typeDescriptions": {
                        "typeIdentifier": "t_uint256",
                        "typeString": "uint256"
                      },
                      "typeName": {
                        "id": 2647,
                        "name": "uint256",
                        "nodeType": "ElementaryTypeName",
                        "src": "2538:7:12",
                        "typeDescriptions": {
                          "typeIdentifier": "t_uint256",
                          "typeString": "uint256"
                        }
                      },
                      "value": null,
                      "visibility": "internal"
                    }
                  ],
                  "id": 2652,
                  "initialValue": {
                    "argumentTypes": null,
                    "commonType": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    },
                    "id": 2651,
                    "isConstant": false,
                    "isLValue": false,
                    "isPure": false,
                    "lValueRequested": false,
                    "leftExpression": {
                      "argumentTypes": null,
                      "id": 2649,
                      "name": "a",
                      "nodeType": "Identifier",
                      "overloadedDeclarations": [],
                      "referencedDeclaration": 2633,
                      "src": "2550:1:12",
                      "typeDescriptions": {
                        "typeIdentifier": "t_uint256",
                        "typeString": "uint256"
                      }
                    },
                    "nodeType": "BinaryOperation",
                    "operator": "*",
                    "rightExpression": {
                      "argumentTypes": null,
                      "id": 2650,
                      "name": "b",
                      "nodeType": "Identifier",
                      "overloadedDeclarations": [],
                      "referencedDeclaration": 2635,
                      "src": "2554:1:12",
                      "typeDescriptions": {
                        "typeIdentifier": "t_uint256",
                        "typeString": "uint256"
                      }
                    },
                    "src": "2550:5:12",
                    "typeDescriptions": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    }
                  },
                  "nodeType": "VariableDeclarationStatement",
                  "src": "2538:17:12"
                },
                {
                  "expression": {
                    "argumentTypes": null,
                    "arguments": [
                      {
                        "argumentTypes": null,
                        "commonType": {
                          "typeIdentifier": "t_uint256",
                          "typeString": "uint256"
                        },
                        "id": 2658,
                        "isConstant": false,
                        "isLValue": false,
                        "isPure": false,
                        "lValueRequested": false,
                        "leftExpression": {
                          "argumentTypes": null,
                          "commonType": {
                            "typeIdentifier": "t_uint256",
                            "typeString": "uint256"
                          },
                          "id": 2656,
                          "isConstant": false,
                          "isLValue": false,
                          "isPure": false,
                          "lValueRequested": false,
                          "leftExpression": {
                            "argumentTypes": null,
                            "id": 2654,
                            "name": "c",
                            "nodeType": "Identifier",
                            "overloadedDeclarations": [],
                            "referencedDeclaration": 2648,
                            "src": "2573:1:12",
                            "typeDescriptions": {
                              "typeIdentifier": "t_uint256",
                              "typeString": "uint256"
                            }
                          },
                          "nodeType": "BinaryOperation",
                          "operator": "/",
                          "rightExpression": {
                            "argumentTypes": null,
                            "id": 2655,
                            "name": "a",
                            "nodeType": "Identifier",
                            "overloadedDeclarations": [],
                            "referencedDeclaration": 2633,
                            "src": "2577:1:12",
                            "typeDescriptions": {
                              "typeIdentifier": "t_uint256",
                              "typeString": "uint256"
                            }
                          },
                          "src": "2573:5:12",
                          "typeDescriptions": {
                            "typeIdentifier": "t_uint256",
                            "typeString": "uint256"
                          }
                        },
                        "nodeType": "BinaryOperation",
                        "operator": "==",
                        "rightExpression": {
                          "argumentTypes": null,
                          "id": 2657,
                          "name": "b",
                          "nodeType": "Identifier",
                          "overloadedDeclarations": [],
                          "referencedDeclaration": 2635,
                          "src": "2582:1:12",
                          "typeDescriptions": {
                            "typeIdentifier": "t_uint256",
                            "typeString": "uint256"
                          }
                        },
                        "src": "2573:10:12",
                        "typeDescriptions": {
                          "typeIdentifier": "t_bool",
                          "typeString": "bool"
                        }
                      },
                      {
                        "argumentTypes": null,
                        "hexValue": "536166654d6174683a206d756c7469706c69636174696f6e206f766572666c6f77",
                        "id": 2659,
                        "isConstant": false,
                        "isLValue": false,
                        "isPure": true,
                        "kind": "string",
                        "lValueRequested": false,
                        "nodeType": "Literal",
                        "src": "2585:35:12",
                        "subdenomination": null,
                        "typeDescriptions": {
                          "typeIdentifier": "t_stringliteral_9113bb53c2876a3805b2c9242029423fc540a728243ce887ab24c82cf119fba3",
                          "typeString": "literal_string \"SafeMath: multiplication overflow\""
                        },
                        "value": "SafeMath: multiplication overflow"
                      }
                    ],
                    "expression": {
                      "argumentTypes": [
                        {
                          "typeIdentifier": "t_bool",
                          "typeString": "bool"
                        },
                        {
                          "typeIdentifier": "t_stringliteral_9113bb53c2876a3805b2c9242029423fc540a728243ce887ab24c82cf119fba3",
                          "typeString": "literal_string \"SafeMath: multiplication overflow\""
                        }
                      ],
                      "id": 2653,
                      "name": "require",
                      "nodeType": "Identifier",
                      "overloadedDeclarations": [
                        -18,
                        -18
                      ],
                      "referencedDeclaration": -18,
                      "src": "2565:7:12",
                      "typeDescriptions": {
                        "typeIdentifier": "t_function_require_pure$_t_bool_$_t_string_memory_ptr_$returns$__$",
                        "typeString": "function (bool,string memory) pure"
                      }
                    },
                    "id": 2660,
                    "isConstant": false,
                    "isLValue": false,
                    "isPure": false,
                    "kind": "functionCall",
                    "lValueRequested": false,
                    "names": [],
                    "nodeType": "FunctionCall",
                    "src": "2565:56:12",
                    "tryCall": false,
                    "typeDescriptions": {
                      "typeIdentifier": "t_tuple$__$",
                      "typeString": "tuple()"
                    }
                  },
                  "id": 2661,
                  "nodeType": "ExpressionStatement",
                  "src": "2565:56:12"
                },
                {
                  "expression": {
                    "argumentTypes": null,
                    "id": 2662,
                    "name": "c",
                    "nodeType": "Identifier",
                    "overloadedDeclarations": [],
                    "referencedDeclaration": 2648,
                    "src": "2639:1:12",
                    "typeDescriptions": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    }
                  },
                  "functionReturnParameters": 2639,
                  "id": 2663,
                  "nodeType": "Return",
                  "src": "2632:8:12"
                }
              ]
            },
            "documentation": {
              "id": 2631,
              "nodeType": "StructuredDocumentation",
              "src": "1947:236:12",
              "text": " @dev Returns the multiplication of two unsigned integers, reverting on\n overflow.\n Counterpart to Solidity's `*` operator.\n Requirements:\n - Multiplication cannot overflow."
            },
            "id": 2665,
            "implemented": true,
            "kind": "function",
            "modifiers": [],
            "name": "mul",
            "nodeType": "FunctionDefinition",
            "overrides": null,
            "parameters": {
              "id": 2636,
              "nodeType": "ParameterList",
              "parameters": [
                {
                  "constant": false,
                  "id": 2633,
                  "mutability": "mutable",
                  "name": "a",
                  "nodeType": "VariableDeclaration",
                  "overrides": null,
                  "scope": 2665,
                  "src": "2201:9:12",
                  "stateVariable": false,
                  "storageLocation": "default",
                  "typeDescriptions": {
                    "typeIdentifier": "t_uint256",
                    "typeString": "uint256"
                  },
                  "typeName": {
                    "id": 2632,
                    "name": "uint256",
                    "nodeType": "ElementaryTypeName",
                    "src": "2201:7:12",
                    "typeDescriptions": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    }
                  },
                  "value": null,
                  "visibility": "internal"
                },
                {
                  "constant": false,
                  "id": 2635,
                  "mutability": "mutable",
                  "name": "b",
                  "nodeType": "VariableDeclaration",
                  "overrides": null,
                  "scope": 2665,
                  "src": "2212:9:12",
                  "stateVariable": false,
                  "storageLocation": "default",
                  "typeDescriptions": {
                    "typeIdentifier": "t_uint256",
                    "typeString": "uint256"
                  },
                  "typeName": {
                    "id": 2634,
                    "name": "uint256",
                    "nodeType": "ElementaryTypeName",
                    "src": "2212:7:12",
                    "typeDescriptions": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    }
                  },
                  "value": null,
                  "visibility": "internal"
                }
              ],
              "src": "2200:22:12"
            },
            "returnParameters": {
              "id": 2639,
              "nodeType": "ParameterList",
              "parameters": [
                {
                  "constant": false,
                  "id": 2638,
                  "mutability": "mutable",
                  "name": "",
                  "nodeType": "VariableDeclaration",
                  "overrides": null,
                  "scope": 2665,
                  "src": "2246:7:12",
                  "stateVariable": false,
                  "storageLocation": "default",
                  "typeDescriptions": {
                    "typeIdentifier": "t_uint256",
                    "typeString": "uint256"
                  },
                  "typeName": {
                    "id": 2637,
                    "name": "uint256",
                    "nodeType": "ElementaryTypeName",
                    "src": "2246:7:12",
                    "typeDescriptions": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    }
                  },
                  "value": null,
                  "visibility": "internal"
                }
              ],
              "src": "2245:9:12"
            },
            "scope": 2752,
            "src": "2188:459:12",
            "stateMutability": "pure",
            "virtual": false,
            "visibility": "internal"
          },
          {
            "body": {
              "id": 2681,
              "nodeType": "Block",
              "src": "3176:63:12",
              "statements": [
                {
                  "expression": {
                    "argumentTypes": null,
                    "arguments": [
                      {
                        "argumentTypes": null,
                        "id": 2676,
                        "name": "a",
                        "nodeType": "Identifier",
                        "overloadedDeclarations": [],
                        "referencedDeclaration": 2668,
                        "src": "3197:1:12",
                        "typeDescriptions": {
                          "typeIdentifier": "t_uint256",
                          "typeString": "uint256"
                        }
                      },
                      {
                        "argumentTypes": null,
                        "id": 2677,
                        "name": "b",
                        "nodeType": "Identifier",
                        "overloadedDeclarations": [],
                        "referencedDeclaration": 2670,
                        "src": "3200:1:12",
                        "typeDescriptions": {
                          "typeIdentifier": "t_uint256",
                          "typeString": "uint256"
                        }
                      },
                      {
                        "argumentTypes": null,
                        "hexValue": "536166654d6174683a206469766973696f6e206279207a65726f",
                        "id": 2678,
                        "isConstant": false,
                        "isLValue": false,
                        "isPure": true,
                        "kind": "string",
                        "lValueRequested": false,
                        "nodeType": "Literal",
                        "src": "3203:28:12",
                        "subdenomination": null,
                        "typeDescriptions": {
                          "typeIdentifier": "t_stringliteral_5b7cc70dda4dc2143e5adb63bd5d1f349504f461dbdfd9bc76fac1f8ca6d019f",
                          "typeString": "literal_string \"SafeMath: division by zero\""
                        },
                        "value": "SafeMath: division by zero"
                      }
                    ],
                    "expression": {
                      "argumentTypes": [
                        {
                          "typeIdentifier": "t_uint256",
                          "typeString": "uint256"
                        },
                        {
                          "typeIdentifier": "t_uint256",
                          "typeString": "uint256"
                        },
                        {
                          "typeIdentifier": "t_stringliteral_5b7cc70dda4dc2143e5adb63bd5d1f349504f461dbdfd9bc76fac1f8ca6d019f",
                          "typeString": "literal_string \"SafeMath: division by zero\""
                        }
                      ],
                      "id": 2675,
                      "name": "div",
                      "nodeType": "Identifier",
                      "overloadedDeclarations": [
                        2682,
                        2710
                      ],
                      "referencedDeclaration": 2710,
                      "src": "3193:3:12",
                      "typeDescriptions": {
                        "typeIdentifier": "t_function_internal_pure$_t_uint256_$_t_uint256_$_t_string_memory_ptr_$returns$_t_uint256_$",
                        "typeString": "function (uint256,uint256,string memory) pure returns (uint256)"
                      }
                    },
                    "id": 2679,
                    "isConstant": false,
                    "isLValue": false,
                    "isPure": false,
                    "kind": "functionCall",
                    "lValueRequested": false,
                    "names": [],
                    "nodeType": "FunctionCall",
                    "src": "3193:39:12",
                    "tryCall": false,
                    "typeDescriptions": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    }
                  },
                  "functionReturnParameters": 2674,
                  "id": 2680,
                  "nodeType": "Return",
                  "src": "3186:46:12"
                }
              ]
            },
            "documentation": {
              "id": 2666,
              "nodeType": "StructuredDocumentation",
              "src": "2653:451:12",
              "text": " @dev Returns the integer division of two unsigned integers. Reverts on\n division by zero. The result is rounded towards zero.\n Counterpart to Solidity's `/` operator. Note: this function uses a\n `revert` opcode (which leaves remaining gas untouched) while Solidity\n uses an invalid opcode to revert (consuming all remaining gas).\n Requirements:\n - The divisor cannot be zero."
            },
            "id": 2682,
            "implemented": true,
            "kind": "function",
            "modifiers": [],
            "name": "div",
            "nodeType": "FunctionDefinition",
            "overrides": null,
            "parameters": {
              "id": 2671,
              "nodeType": "ParameterList",
              "parameters": [
                {
                  "constant": false,
                  "id": 2668,
                  "mutability": "mutable",
                  "name": "a",
                  "nodeType": "VariableDeclaration",
                  "overrides": null,
                  "scope": 2682,
                  "src": "3122:9:12",
                  "stateVariable": false,
                  "storageLocation": "default",
                  "typeDescriptions": {
                    "typeIdentifier": "t_uint256",
                    "typeString": "uint256"
                  },
                  "typeName": {
                    "id": 2667,
                    "name": "uint256",
                    "nodeType": "ElementaryTypeName",
                    "src": "3122:7:12",
                    "typeDescriptions": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    }
                  },
                  "value": null,
                  "visibility": "internal"
                },
                {
                  "constant": false,
                  "id": 2670,
                  "mutability": "mutable",
                  "name": "b",
                  "nodeType": "VariableDeclaration",
                  "overrides": null,
                  "scope": 2682,
                  "src": "3133:9:12",
                  "stateVariable": false,
                  "storageLocation": "default",
                  "typeDescriptions": {
                    "typeIdentifier": "t_uint256",
                    "typeString": "uint256"
                  },
                  "typeName": {
                    "id": 2669,
                    "name": "uint256",
                    "nodeType": "ElementaryTypeName",
                    "src": "3133:7:12",
                    "typeDescriptions": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    }
                  },
                  "value": null,
                  "visibility": "internal"
                }
              ],
              "src": "3121:22:12"
            },
            "returnParameters": {
              "id": 2674,
              "nodeType": "ParameterList",
              "parameters": [
                {
                  "constant": false,
                  "id": 2673,
                  "mutability": "mutable",
                  "name": "",
                  "nodeType": "VariableDeclaration",
                  "overrides": null,
                  "scope": 2682,
                  "src": "3167:7:12",
                  "stateVariable": false,
                  "storageLocation": "default",
                  "typeDescriptions": {
                    "typeIdentifier": "t_uint256",
                    "typeString": "uint256"
                  },
                  "typeName": {
                    "id": 2672,
                    "name": "uint256",
                    "nodeType": "ElementaryTypeName",
                    "src": "3167:7:12",
                    "typeDescriptions": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    }
                  },
                  "value": null,
                  "visibility": "internal"
                }
              ],
              "src": "3166:9:12"
            },
            "scope": 2752,
            "src": "3109:130:12",
            "stateMutability": "pure",
            "virtual": false,
            "visibility": "internal"
          },
          {
            "body": {
              "id": 2709,
              "nodeType": "Block",
              "src": "3816:177:12",
              "statements": [
                {
                  "expression": {
                    "argumentTypes": null,
                    "arguments": [
                      {
                        "argumentTypes": null,
                        "commonType": {
                          "typeIdentifier": "t_uint256",
                          "typeString": "uint256"
                        },
                        "id": 2697,
                        "isConstant": false,
                        "isLValue": false,
                        "isPure": false,
                        "lValueRequested": false,
                        "leftExpression": {
                          "argumentTypes": null,
                          "id": 2695,
                          "name": "b",
                          "nodeType": "Identifier",
                          "overloadedDeclarations": [],
                          "referencedDeclaration": 2687,
                          "src": "3834:1:12",
                          "typeDescriptions": {
                            "typeIdentifier": "t_uint256",
                            "typeString": "uint256"
                          }
                        },
                        "nodeType": "BinaryOperation",
                        "operator": ">",
                        "rightExpression": {
                          "argumentTypes": null,
                          "hexValue": "30",
                          "id": 2696,
                          "isConstant": false,
                          "isLValue": false,
                          "isPure": true,
                          "kind": "number",
                          "lValueRequested": false,
                          "nodeType": "Literal",
                          "src": "3838:1:12",
                          "subdenomination": null,
                          "typeDescriptions": {
                            "typeIdentifier": "t_rational_0_by_1",
                            "typeString": "int_const 0"
                          },
                          "value": "0"
                        },
                        "src": "3834:5:12",
                        "typeDescriptions": {
                          "typeIdentifier": "t_bool",
                          "typeString": "bool"
                        }
                      },
                      {
                        "argumentTypes": null,
                        "id": 2698,
                        "name": "errorMessage",
                        "nodeType": "Identifier",
                        "overloadedDeclarations": [],
                        "referencedDeclaration": 2689,
                        "src": "3841:12:12",
                        "typeDescriptions": {
                          "typeIdentifier": "t_string_memory_ptr",
                          "typeString": "string memory"
                        }
                      }
                    ],
                    "expression": {
                      "argumentTypes": [
                        {
                          "typeIdentifier": "t_bool",
                          "typeString": "bool"
                        },
                        {
                          "typeIdentifier": "t_string_memory_ptr",
                          "typeString": "string memory"
                        }
                      ],
                      "id": 2694,
                      "name": "require",
                      "nodeType": "Identifier",
                      "overloadedDeclarations": [
                        -18,
                        -18
                      ],
                      "referencedDeclaration": -18,
                      "src": "3826:7:12",
                      "typeDescriptions": {
                        "typeIdentifier": "t_function_require_pure$_t_bool_$_t_string_memory_ptr_$returns$__$",
                        "typeString": "function (bool,string memory) pure"
                      }
                    },
                    "id": 2699,
                    "isConstant": false,
                    "isLValue": false,
                    "isPure": false,
                    "kind": "functionCall",
                    "lValueRequested": false,
                    "names": [],
                    "nodeType": "FunctionCall",
                    "src": "3826:28:12",
                    "tryCall": false,
                    "typeDescriptions": {
                      "typeIdentifier": "t_tuple$__$",
                      "typeString": "tuple()"
                    }
                  },
                  "id": 2700,
                  "nodeType": "ExpressionStatement",
                  "src": "3826:28:12"
                },
                {
                  "assignments": [
                    2702
                  ],
                  "declarations": [
                    {
                      "constant": false,
                      "id": 2702,
                      "mutability": "mutable",
                      "name": "c",
                      "nodeType": "VariableDeclaration",
                      "overrides": null,
                      "scope": 2709,
                      "src": "3864:9:12",
                      "stateVariable": false,
                      "storageLocation": "default",
                      "typeDescriptions": {
                        "typeIdentifier": "t_uint256",
                        "typeString": "uint256"
                      },
                      "typeName": {
                        "id": 2701,
                        "name": "uint256",
                        "nodeType": "ElementaryTypeName",
                        "src": "3864:7:12",
                        "typeDescriptions": {
                          "typeIdentifier": "t_uint256",
                          "typeString": "uint256"
                        }
                      },
                      "value": null,
                      "visibility": "internal"
                    }
                  ],
                  "id": 2706,
                  "initialValue": {
                    "argumentTypes": null,
                    "commonType": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    },
                    "id": 2705,
                    "isConstant": false,
                    "isLValue": false,
                    "isPure": false,
                    "lValueRequested": false,
                    "leftExpression": {
                      "argumentTypes": null,
                      "id": 2703,
                      "name": "a",
                      "nodeType": "Identifier",
                      "overloadedDeclarations": [],
                      "referencedDeclaration": 2685,
                      "src": "3876:1:12",
                      "typeDescriptions": {
                        "typeIdentifier": "t_uint256",
                        "typeString": "uint256"
                      }
                    },
                    "nodeType": "BinaryOperation",
                    "operator": "/",
                    "rightExpression": {
                      "argumentTypes": null,
                      "id": 2704,
                      "name": "b",
                      "nodeType": "Identifier",
                      "overloadedDeclarations": [],
                      "referencedDeclaration": 2687,
                      "src": "3880:1:12",
                      "typeDescriptions": {
                        "typeIdentifier": "t_uint256",
                        "typeString": "uint256"
                      }
                    },
                    "src": "3876:5:12",
                    "typeDescriptions": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    }
                  },
                  "nodeType": "VariableDeclarationStatement",
                  "src": "3864:17:12"
                },
                {
                  "expression": {
                    "argumentTypes": null,
                    "id": 2707,
                    "name": "c",
                    "nodeType": "Identifier",
                    "overloadedDeclarations": [],
                    "referencedDeclaration": 2702,
                    "src": "3985:1:12",
                    "typeDescriptions": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    }
                  },
                  "functionReturnParameters": 2693,
                  "id": 2708,
                  "nodeType": "Return",
                  "src": "3978:8:12"
                }
              ]
            },
            "documentation": {
              "id": 2683,
              "nodeType": "StructuredDocumentation",
              "src": "3245:471:12",
              "text": " @dev Returns the integer division of two unsigned integers. Reverts with custom message on\n division by zero. The result is rounded towards zero.\n Counterpart to Solidity's `/` operator. Note: this function uses a\n `revert` opcode (which leaves remaining gas untouched) while Solidity\n uses an invalid opcode to revert (consuming all remaining gas).\n Requirements:\n - The divisor cannot be zero."
            },
            "id": 2710,
            "implemented": true,
            "kind": "function",
            "modifiers": [],
            "name": "div",
            "nodeType": "FunctionDefinition",
            "overrides": null,
            "parameters": {
              "id": 2690,
              "nodeType": "ParameterList",
              "parameters": [
                {
                  "constant": false,
                  "id": 2685,
                  "mutability": "mutable",
                  "name": "a",
                  "nodeType": "VariableDeclaration",
                  "overrides": null,
                  "scope": 2710,
                  "src": "3734:9:12",
                  "stateVariable": false,
                  "storageLocation": "default",
                  "typeDescriptions": {
                    "typeIdentifier": "t_uint256",
                    "typeString": "uint256"
                  },
                  "typeName": {
                    "id": 2684,
                    "name": "uint256",
                    "nodeType": "ElementaryTypeName",
                    "src": "3734:7:12",
                    "typeDescriptions": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    }
                  },
                  "value": null,
                  "visibility": "internal"
                },
                {
                  "constant": false,
                  "id": 2687,
                  "mutability": "mutable",
                  "name": "b",
                  "nodeType": "VariableDeclaration",
                  "overrides": null,
                  "scope": 2710,
                  "src": "3745:9:12",
                  "stateVariable": false,
                  "storageLocation": "default",
                  "typeDescriptions": {
                    "typeIdentifier": "t_uint256",
                    "typeString": "uint256"
                  },
                  "typeName": {
                    "id": 2686,
                    "name": "uint256",
                    "nodeType": "ElementaryTypeName",
                    "src": "3745:7:12",
                    "typeDescriptions": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    }
                  },
                  "value": null,
                  "visibility": "internal"
                },
                {
                  "constant": false,
                  "id": 2689,
                  "mutability": "mutable",
                  "name": "errorMessage",
                  "nodeType": "VariableDeclaration",
                  "overrides": null,
                  "scope": 2710,
                  "src": "3756:26:12",
                  "stateVariable": false,
                  "storageLocation": "memory",
                  "typeDescriptions": {
                    "typeIdentifier": "t_string_memory_ptr",
                    "typeString": "string"
                  },
                  "typeName": {
                    "id": 2688,
                    "name": "string",
                    "nodeType": "ElementaryTypeName",
                    "src": "3756:6:12",
                    "typeDescriptions": {
                      "typeIdentifier": "t_string_storage_ptr",
                      "typeString": "string"
                    }
                  },
                  "value": null,
                  "visibility": "internal"
                }
              ],
              "src": "3733:50:12"
            },
            "returnParameters": {
              "id": 2693,
              "nodeType": "ParameterList",
              "parameters": [
                {
                  "constant": false,
                  "id": 2692,
                  "mutability": "mutable",
                  "name": "",
                  "nodeType": "VariableDeclaration",
                  "overrides": null,
                  "scope": 2710,
                  "src": "3807:7:12",
                  "stateVariable": false,
                  "storageLocation": "default",
                  "typeDescriptions": {
                    "typeIdentifier": "t_uint256",
                    "typeString": "uint256"
                  },
                  "typeName": {
                    "id": 2691,
                    "name": "uint256",
                    "nodeType": "ElementaryTypeName",
                    "src": "3807:7:12",
                    "typeDescriptions": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    }
                  },
                  "value": null,
                  "visibility": "internal"
                }
              ],
              "src": "3806:9:12"
            },
            "scope": 2752,
            "src": "3721:272:12",
            "stateMutability": "pure",
            "virtual": false,
            "visibility": "internal"
          },
          {
            "body": {
              "id": 2726,
              "nodeType": "Block",
              "src": "4511:61:12",
              "statements": [
                {
                  "expression": {
                    "argumentTypes": null,
                    "arguments": [
                      {
                        "argumentTypes": null,
                        "id": 2721,
                        "name": "a",
                        "nodeType": "Identifier",
                        "overloadedDeclarations": [],
                        "referencedDeclaration": 2713,
                        "src": "4532:1:12",
                        "typeDescriptions": {
                          "typeIdentifier": "t_uint256",
                          "typeString": "uint256"
                        }
                      },
                      {
                        "argumentTypes": null,
                        "id": 2722,
                        "name": "b",
                        "nodeType": "Identifier",
                        "overloadedDeclarations": [],
                        "referencedDeclaration": 2715,
                        "src": "4535:1:12",
                        "typeDescriptions": {
                          "typeIdentifier": "t_uint256",
                          "typeString": "uint256"
                        }
                      },
                      {
                        "argumentTypes": null,
                        "hexValue": "536166654d6174683a206d6f64756c6f206279207a65726f",
                        "id": 2723,
                        "isConstant": false,
                        "isLValue": false,
                        "isPure": true,
                        "kind": "string",
                        "lValueRequested": false,
                        "nodeType": "Literal",
                        "src": "4538:26:12",
                        "subdenomination": null,
                        "typeDescriptions": {
                          "typeIdentifier": "t_stringliteral_726e51f7b81fce0a68f5f214f445e275313b20b1633f08ce954ee39abf8d7832",
                          "typeString": "literal_string \"SafeMath: modulo by zero\""
                        },
                        "value": "SafeMath: modulo by zero"
                      }
                    ],
                    "expression": {
                      "argumentTypes": [
                        {
                          "typeIdentifier": "t_uint256",
                          "typeString": "uint256"
                        },
                        {
                          "typeIdentifier": "t_uint256",
                          "typeString": "uint256"
                        },
                        {
                          "typeIdentifier": "t_stringliteral_726e51f7b81fce0a68f5f214f445e275313b20b1633f08ce954ee39abf8d7832",
                          "typeString": "literal_string \"SafeMath: modulo by zero\""
                        }
                      ],
                      "id": 2720,
                      "name": "mod",
                      "nodeType": "Identifier",
                      "overloadedDeclarations": [
                        2727,
                        2751
                      ],
                      "referencedDeclaration": 2751,
                      "src": "4528:3:12",
                      "typeDescriptions": {
                        "typeIdentifier": "t_function_internal_pure$_t_uint256_$_t_uint256_$_t_string_memory_ptr_$returns$_t_uint256_$",
                        "typeString": "function (uint256,uint256,string memory) pure returns (uint256)"
                      }
                    },
                    "id": 2724,
                    "isConstant": false,
                    "isLValue": false,
                    "isPure": false,
                    "kind": "functionCall",
                    "lValueRequested": false,
                    "names": [],
                    "nodeType": "FunctionCall",
                    "src": "4528:37:12",
                    "tryCall": false,
                    "typeDescriptions": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    }
                  },
                  "functionReturnParameters": 2719,
                  "id": 2725,
                  "nodeType": "Return",
                  "src": "4521:44:12"
                }
              ]
            },
            "documentation": {
              "id": 2711,
              "nodeType": "StructuredDocumentation",
              "src": "3999:440:12",
              "text": " @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),\n Reverts when dividing by zero.\n Counterpart to Solidity's `%` operator. This function uses a `revert`\n opcode (which leaves remaining gas untouched) while Solidity uses an\n invalid opcode to revert (consuming all remaining gas).\n Requirements:\n - The divisor cannot be zero."
            },
            "id": 2727,
            "implemented": true,
            "kind": "function",
            "modifiers": [],
            "name": "mod",
            "nodeType": "FunctionDefinition",
            "overrides": null,
            "parameters": {
              "id": 2716,
              "nodeType": "ParameterList",
              "parameters": [
                {
                  "constant": false,
                  "id": 2713,
                  "mutability": "mutable",
                  "name": "a",
                  "nodeType": "VariableDeclaration",
                  "overrides": null,
                  "scope": 2727,
                  "src": "4457:9:12",
                  "stateVariable": false,
                  "storageLocation": "default",
                  "typeDescriptions": {
                    "typeIdentifier": "t_uint256",
                    "typeString": "uint256"
                  },
                  "typeName": {
                    "id": 2712,
                    "name": "uint256",
                    "nodeType": "ElementaryTypeName",
                    "src": "4457:7:12",
                    "typeDescriptions": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    }
                  },
                  "value": null,
                  "visibility": "internal"
                },
                {
                  "constant": false,
                  "id": 2715,
                  "mutability": "mutable",
                  "name": "b",
                  "nodeType": "VariableDeclaration",
                  "overrides": null,
                  "scope": 2727,
                  "src": "4468:9:12",
                  "stateVariable": false,
                  "storageLocation": "default",
                  "typeDescriptions": {
                    "typeIdentifier": "t_uint256",
                    "typeString": "uint256"
                  },
                  "typeName": {
                    "id": 2714,
                    "name": "uint256",
                    "nodeType": "ElementaryTypeName",
                    "src": "4468:7:12",
                    "typeDescriptions": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    }
                  },
                  "value": null,
                  "visibility": "internal"
                }
              ],
              "src": "4456:22:12"
            },
            "returnParameters": {
              "id": 2719,
              "nodeType": "ParameterList",
              "parameters": [
                {
                  "constant": false,
                  "id": 2718,
                  "mutability": "mutable",
                  "name": "",
                  "nodeType": "VariableDeclaration",
                  "overrides": null,
                  "scope": 2727,
                  "src": "4502:7:12",
                  "stateVariable": false,
                  "storageLocation": "default",
                  "typeDescriptions": {
                    "typeIdentifier": "t_uint256",
                    "typeString": "uint256"
                  },
                  "typeName": {
                    "id": 2717,
                    "name": "uint256",
                    "nodeType": "ElementaryTypeName",
                    "src": "4502:7:12",
                    "typeDescriptions": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    }
                  },
                  "value": null,
                  "visibility": "internal"
                }
              ],
              "src": "4501:9:12"
            },
            "scope": 2752,
            "src": "4444:128:12",
            "stateMutability": "pure",
            "virtual": false,
            "visibility": "internal"
          },
          {
            "body": {
              "id": 2750,
              "nodeType": "Block",
              "src": "5138:68:12",
              "statements": [
                {
                  "expression": {
                    "argumentTypes": null,
                    "arguments": [
                      {
                        "argumentTypes": null,
                        "commonType": {
                          "typeIdentifier": "t_uint256",
                          "typeString": "uint256"
                        },
                        "id": 2742,
                        "isConstant": false,
                        "isLValue": false,
                        "isPure": false,
                        "lValueRequested": false,
                        "leftExpression": {
                          "argumentTypes": null,
                          "id": 2740,
                          "name": "b",
                          "nodeType": "Identifier",
                          "overloadedDeclarations": [],
                          "referencedDeclaration": 2732,
                          "src": "5156:1:12",
                          "typeDescriptions": {
                            "typeIdentifier": "t_uint256",
                            "typeString": "uint256"
                          }
                        },
                        "nodeType": "BinaryOperation",
                        "operator": "!=",
                        "rightExpression": {
                          "argumentTypes": null,
                          "hexValue": "30",
                          "id": 2741,
                          "isConstant": false,
                          "isLValue": false,
                          "isPure": true,
                          "kind": "number",
                          "lValueRequested": false,
                          "nodeType": "Literal",
                          "src": "5161:1:12",
                          "subdenomination": null,
                          "typeDescriptions": {
                            "typeIdentifier": "t_rational_0_by_1",
                            "typeString": "int_const 0"
                          },
                          "value": "0"
                        },
                        "src": "5156:6:12",
                        "typeDescriptions": {
                          "typeIdentifier": "t_bool",
                          "typeString": "bool"
                        }
                      },
                      {
                        "argumentTypes": null,
                        "id": 2743,
                        "name": "errorMessage",
                        "nodeType": "Identifier",
                        "overloadedDeclarations": [],
                        "referencedDeclaration": 2734,
                        "src": "5164:12:12",
                        "typeDescriptions": {
                          "typeIdentifier": "t_string_memory_ptr",
                          "typeString": "string memory"
                        }
                      }
                    ],
                    "expression": {
                      "argumentTypes": [
                        {
                          "typeIdentifier": "t_bool",
                          "typeString": "bool"
                        },
                        {
                          "typeIdentifier": "t_string_memory_ptr",
                          "typeString": "string memory"
                        }
                      ],
                      "id": 2739,
                      "name": "require",
                      "nodeType": "Identifier",
                      "overloadedDeclarations": [
                        -18,
                        -18
                      ],
                      "referencedDeclaration": -18,
                      "src": "5148:7:12",
                      "typeDescriptions": {
                        "typeIdentifier": "t_function_require_pure$_t_bool_$_t_string_memory_ptr_$returns$__$",
                        "typeString": "function (bool,string memory) pure"
                      }
                    },
                    "id": 2744,
                    "isConstant": false,
                    "isLValue": false,
                    "isPure": false,
                    "kind": "functionCall",
                    "lValueRequested": false,
                    "names": [],
                    "nodeType": "FunctionCall",
                    "src": "5148:29:12",
                    "tryCall": false,
                    "typeDescriptions": {
                      "typeIdentifier": "t_tuple$__$",
                      "typeString": "tuple()"
                    }
                  },
                  "id": 2745,
                  "nodeType": "ExpressionStatement",
                  "src": "5148:29:12"
                },
                {
                  "expression": {
                    "argumentTypes": null,
                    "commonType": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    },
                    "id": 2748,
                    "isConstant": false,
                    "isLValue": false,
                    "isPure": false,
                    "lValueRequested": false,
                    "leftExpression": {
                      "argumentTypes": null,
                      "id": 2746,
                      "name": "a",
                      "nodeType": "Identifier",
                      "overloadedDeclarations": [],
                      "referencedDeclaration": 2730,
                      "src": "5194:1:12",
                      "typeDescriptions": {
                        "typeIdentifier": "t_uint256",
                        "typeString": "uint256"
                      }
                    },
                    "nodeType": "BinaryOperation",
                    "operator": "%",
                    "rightExpression": {
                      "argumentTypes": null,
                      "id": 2747,
                      "name": "b",
                      "nodeType": "Identifier",
                      "overloadedDeclarations": [],
                      "referencedDeclaration": 2732,
                      "src": "5198:1:12",
                      "typeDescriptions": {
                        "typeIdentifier": "t_uint256",
                        "typeString": "uint256"
                      }
                    },
                    "src": "5194:5:12",
                    "typeDescriptions": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    }
                  },
                  "functionReturnParameters": 2738,
                  "id": 2749,
                  "nodeType": "Return",
                  "src": "5187:12:12"
                }
              ]
            },
            "documentation": {
              "id": 2728,
              "nodeType": "StructuredDocumentation",
              "src": "4578:460:12",
              "text": " @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),\n Reverts with custom message when dividing by zero.\n Counterpart to Solidity's `%` operator. This function uses a `revert`\n opcode (which leaves remaining gas untouched) while Solidity uses an\n invalid opcode to revert (consuming all remaining gas).\n Requirements:\n - The divisor cannot be zero."
            },
            "id": 2751,
            "implemented": true,
            "kind": "function",
            "modifiers": [],
            "name": "mod",
            "nodeType": "FunctionDefinition",
            "overrides": null,
            "parameters": {
              "id": 2735,
              "nodeType": "ParameterList",
              "parameters": [
                {
                  "constant": false,
                  "id": 2730,
                  "mutability": "mutable",
                  "name": "a",
                  "nodeType": "VariableDeclaration",
                  "overrides": null,
                  "scope": 2751,
                  "src": "5056:9:12",
                  "stateVariable": false,
                  "storageLocation": "default",
                  "typeDescriptions": {
                    "typeIdentifier": "t_uint256",
                    "typeString": "uint256"
                  },
                  "typeName": {
                    "id": 2729,
                    "name": "uint256",
                    "nodeType": "ElementaryTypeName",
                    "src": "5056:7:12",
                    "typeDescriptions": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    }
                  },
                  "value": null,
                  "visibility": "internal"
                },
                {
                  "constant": false,
                  "id": 2732,
                  "mutability": "mutable",
                  "name": "b",
                  "nodeType": "VariableDeclaration",
                  "overrides": null,
                  "scope": 2751,
                  "src": "5067:9:12",
                  "stateVariable": false,
                  "storageLocation": "default",
                  "typeDescriptions": {
                    "typeIdentifier": "t_uint256",
                    "typeString": "uint256"
                  },
                  "typeName": {
                    "id": 2731,
                    "name": "uint256",
                    "nodeType": "ElementaryTypeName",
                    "src": "5067:7:12",
                    "typeDescriptions": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    }
                  },
                  "value": null,
                  "visibility": "internal"
                },
                {
                  "constant": false,
                  "id": 2734,
                  "mutability": "mutable",
                  "name": "errorMessage",
                  "nodeType": "VariableDeclaration",
                  "overrides": null,
                  "scope": 2751,
                  "src": "5078:26:12",
                  "stateVariable": false,
                  "storageLocation": "memory",
                  "typeDescriptions": {
                    "typeIdentifier": "t_string_memory_ptr",
                    "typeString": "string"
                  },
                  "typeName": {
                    "id": 2733,
                    "name": "string",
                    "nodeType": "ElementaryTypeName",
                    "src": "5078:6:12",
                    "typeDescriptions": {
                      "typeIdentifier": "t_string_storage_ptr",
                      "typeString": "string"
                    }
                  },
                  "value": null,
                  "visibility": "internal"
                }
              ],
              "src": "5055:50:12"
            },
            "returnParameters": {
              "id": 2738,
              "nodeType": "ParameterList",
              "parameters": [
                {
                  "constant": false,
                  "id": 2737,
                  "mutability": "mutable",
                  "name": "",
                  "nodeType": "VariableDeclaration",
                  "overrides": null,
                  "scope": 2751,
                  "src": "5129:7:12",
                  "stateVariable": false,
                  "storageLocation": "default",
                  "typeDescriptions": {
                    "typeIdentifier": "t_uint256",
                    "typeString": "uint256"
                  },
                  "typeName": {
                    "id": 2736,
                    "name": "uint256",
                    "nodeType": "ElementaryTypeName",
                    "src": "5129:7:12",
                    "typeDescriptions": {
                      "typeIdentifier": "t_uint256",
                      "typeString": "uint256"
                    }
                  },
                  "value": null,
                  "visibility": "internal"
                }
              ],
              "src": "5128:9:12"
            },
            "scope": 2752,
            "src": "5043:163:12",
            "stateMutability": "pure",
            "virtual": false,
            "visibility": "internal"
          }
        ],
        "scope": 2753,
        "src": "630:4578:12"
      }
    ],
    "src": "33:5176:12"
  },
  "compiler": {
    "name": "solc",
    "version": "0.6.12+commit.27d51765.Emscripten.clang"
  },
  "networks": {},
  "schemaVersion": "3.3.2",
  "updatedAt": "2021-03-04T12:24:19.871Z",
  "devdoc": {
    "details": "Wrappers over Solidity's arithmetic operations with added overflow checks. Arithmetic operations in Solidity wrap on overflow. This can easily result in bugs, because programmers usually assume that an overflow raises an error, which is the standard behavior in high level programming languages. `SafeMath` restores this intuition by reverting the transaction when an operation overflows. Using this library instead of the unchecked operations eliminates an entire class of bugs, so it's recommended to use it always.",
    "kind": "dev",
    "methods": {},
    "version": 1
  },
  "userdoc": {
    "kind": "user",
    "methods": {},
    "version": 1
  }
}