def _has_flush(self):
        '''
        Check the existence of flush cards
        Returns:
            True: exist
            False: not exist
        '''
        if len(self.flush_cards) > 0:
            return True
        else:
            return False

        Check the existence of flush cards
        Returns:
            True: exist
            False: not exist
        
rlcard/games/limitholdem/utils.py