<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def ltrim(self, name, start, end):
 """ Trim the list from start to end. :param name: str the name of the redis key :param start: :param end: :return: Future() """

        with self.pipe as pipe:
            return pipe.ltrim(self.redis_key(name), start, end)