contract ERC20TokenBankInterface{
  //function balance() public view returns(uint);
 // function token() public view returns(address, string memory);
  function issue(address _to, uint _amount) public returns (bool success);
}
function issue(address _to, uint _amount) public returns (bool success);
//function balance() public view returns(uint);
// function token() public view returns(address, string memory);