pragma solidity ^0.5.0; import "../utils/Address.sol"; contract AddressImpl { function isContract(address account) external view returns (bool) { return Address.isContract(account); } function toPayable(address account) external pure returns (address payable) { return Address.toPayable(account); } function sendValue(address payable receiver, uint256 amount) external { Address.sendValue(receiver, amount); } function () external payable { } // sendValue's tests require the contract to hold Ether }