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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _clear(self, pipe=None):
 """Helper for clear operations. :param pipe: Redis pipe in case update is performed as a part of transaction. :type pipe: :class:`redis.client.StrictPipeline` or :class:`redis.client.StrictRedis` """

        redis = self.redis if pipe is None else pipe
        redis.delete(self.key)