code: def _clear(self, pipe=None):
          
          redis = self.redis if pipe is None else pipe
          redis.delete(self.key)
docs: 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`