pragma solidity ^0.5.16; import "../SafeDecimalMath.sol"; contract MockEtherCollateral { using SafeMath for uint; using SafeDecimalMath for uint; uint public totalIssuedSynths; constructor() public {} // Mock openLoan function function openLoan(uint amount) external { // Increment totalIssuedSynths totalIssuedSynths = totalIssuedSynths.add(amount); } function closeLoan(uint amount) external { // Increment totalIssuedSynths totalIssuedSynths = totalIssuedSynths.sub(amount); } }