def end_date(self):
        """账户的交易结束日期(只在回测中使用)

        Raises:
            RuntimeWarning -- [description]

        Returns:
            [type] -- [description]
        """
        if self.start_==None:
            if len(self.time_index_max) > 0:
                return str(max(self.time_index_max))[0:10]
            else:
                print(
                    RuntimeWarning(
                        'QAACCOUNT: THIS ACCOUNT DOESNOT HAVE ANY TRADE'
                    )
                )
        else:
            return self.end_