[
    {
        "constant": true,
        "inputs": [
            {
                "internalType": "address",
                "name": "sourceTokenAddress",
                "type": "address"
            },
            {
                "internalType": "address",
                "name": "destTokenAddress",
                "type": "address"
            },
            {
                "internalType": "uint256",
                "name": "sourceTokenAmount",
                "type": "uint256"
            },
            {
                "internalType": "address",
                "name": "optionalContractAddress",
                "type": "address"
            }
        ],
        "name": "internalExpectedRate",
        "outputs": [
            {
                "internalType": "uint256",
                "name": "",
                "type": "uint256"
            }
        ],
        "payable": false,
        "stateMutability": "view",
        "type": "function"
    },
    {
        "constant": true,
        "inputs": [
            {
                "internalType": "address",
                "name": "sourceTokenAddress",
                "type": "address"
            },
            {
                "internalType": "address",
                "name": "destTokenAddress",
                "type": "address"
            },
            {
                "internalType": "uint256",
                "name": "sourceTokenAmount",
                "type": "uint256"
            },
            {
                "internalType": "address",
                "name": "sovrynSwapContractRegistryAddress",
                "type": "address"
            }
        ],
        "name": "internalExpectedReturn",
        "outputs": [
            {
                "internalType": "uint256",
                "name": "expectedReturn",
                "type": "uint256"
            }
        ],
        "payable": false,
        "stateMutability": "view",
        "type": "function"
    },
    {
        "constant": false,
        "inputs": [
            {
                "internalType": "address",
                "name": "sourceTokenAddress",
                "type": "address"
            },
            {
                "internalType": "address",
                "name": "destTokenAddress",
                "type": "address"
            },
            {
                "internalType": "address",
                "name": "receiverAddress",
                "type": "address"
            },
            {
                "internalType": "address",
                "name": "returnToSenderAddress",
                "type": "address"
            },
            {
                "internalType": "uint256",
                "name": "minSourceTokenAmount",
                "type": "uint256"
            },
            {
                "internalType": "uint256",
                "name": "maxSourceTokenAmount",
                "type": "uint256"
            },
            {
                "internalType": "uint256",
                "name": "requiredDestTokenAmount",
                "type": "uint256"
            }
        ],
        "name": "internalSwap",
        "outputs": [
            {
                "internalType": "uint256",
                "name": "destTokenAmountReceived",
                "type": "uint256"
            },
            {
                "internalType": "uint256",
                "name": "sourceTokenAmountUsed",
                "type": "uint256"
            }
        ],
        "payable": true,
        "stateMutability": "payable",
        "type": "function"
    }
]