contract Token {
    // using SafeMath for uint256;
    //代币总量
    uint256 public totalSupply;
    //获取账号余额
    function balanceOf(address _owner) public view returns(uint256 balance);
    //转账
    function transfer(address _to,uint256 _value) public returns(bool success);
    function transferFrom(address _from,address _to,uint256 _value)public returns(bool success);
    function approve(address _spender,uint256 _value)public returns(bool success);
    function allowance(address _owner, address _spender) public view returns (uint256 remaining);
   //监听转账事件端口
    event Transfer(address indexed _from, address indexed _to, uint256 _value);
    event Approval(address indexed _owner, address indexed _spender, uint256 _value);
}
function transfer(address _to,uint256 _value) public returns(bool success);
//转账