pragma solidity ^0.5.2; import "../token/ERC20/ERC20.sol"; // mock class using ERC20 contract ERC20Mock is ERC20 { constructor (address initialAccount, uint256 initialBalance) public { _mint(initialAccount, initialBalance); } function mint(address account, uint256 amount) public { _mint(account, amount); } function burn(address account, uint256 amount) public { _burn(account, amount); } function burnFrom(address account, uint256 amount) public { _burnFrom(account, amount); } function approveInternal(address owner, address spender, uint256 value) public { _approve(owner, spender, value); } }