pragma solidity ^0.5.7; interface ERC20 { function totalSupply() external view returns (uint256); function balanceOf(address who) external view returns (uint256); function transfer (address to, uint256 value) external returns (bool); function approve(address spender, uint256 value) external returns (bool); function allowance(address owner, address spender) external view returns (uint256); function transferFrom(address from, address to, uint256 value) external returns (bool); event Transfer(address indexed from, address indexed to, uint256 value); event Approval(address indexed owner, address indexed spender, uint256 value); }
0.4.18