pragma solidity ^0.5.2; import "./Escrow.sol"; /** * @title ConditionalEscrow * @dev Base abstract escrow to only allow withdrawal if a condition is met. * @dev Intended usage: See Escrow.sol. Same usage guidelines apply here. */ contract ConditionalEscrow is Escrow { /** * @dev Returns whether an address is allowed to withdraw their funds. To be * implemented by derived contracts. * @param payee The destination address of the funds. */ function withdrawalAllowed(address payee) public view returns (bool); function withdraw(address payable payee) public { require(withdrawalAllowed(payee)); super.withdraw(payee); } }