class_docstr: A memory backend which transfers the experiences from the rollout to the training worker using Redis Pub/Sub in
  Coach when distributed mode is used.
docstr: :param num_consecutive_playing_steps: The number steps to fetch.
docstr_tok: [":","param","num_consecutive_playing_steps",":","The","number","steps","to","fetch","."]
code: def fetch(self, num_consecutive_playing_steps=None):
      """
      :param num_consecutive_playing_steps: The number steps to fetch.
      """
      return RedisSub(
          redis_address=self.params.redis_address,
          redis_port=self.params.redis_port,
          channel=self.params.channel,
      ).run(num_consecutive_playing_steps)
  
imports: import redis
  import pickle
  import uuid
  import time
  from rl_coach.memories.backend.memory import MemoryBackend, MemoryBackendParameters
  from rl_coach.core_types import Transition, Episode, EnvironmentSteps, EnvironmentEpisodes
  from rl_coach.logger import screen
label_desc: Use image node_id 7 for calling the RedisPubSubBackend obj's underlying member method code with example usage: obj.fetch(num_consecutive_playing_steps) and returns: RedisSub