code: def _batch_reader(self):
      return self._reader
  
imports: import gym
  import numpy
  import os
  from six.moves import queue
  import time
  import threading
  import parl
  import paddle
  from atari_model import AtariModel
  from atari_agent import AtariAgent
  from parl.env.atari_wrappers import wrap_deepmind
  from parl.utils import logger, summary
  from parl.utils.scheduler import PiecewiseScheduler
  from parl.utils.time_stat import TimeStat
  from parl.utils.window_stat import WindowStat
  from actor import Actor
label_desc: Use image node_id 3 for calling the Learner obj's underlying member method code with example usage: obj._batch_reader() and returns: self