code: def setUp(self):
      super(BatchDQNAgentTest, self).setUp()
      self._test_subdir = os.path.join("/tmp/dopamine_tests", "ckpts")
      shutil.rmtree(self._test_subdir, ignore_errors=True)
      os.makedirs(self._test_subdir)
      self.num_actions = 4
      self.min_replay_history = 6
      self.update_period = 2
      self.target_update_period = 4
      self.epsilon_decay_period = 90
      self.epsilon_train = 0.05
      self.observation_shape = dqn_agent.NATURE_DQN_OBSERVATION_SHAPE
      self.stack_size = dqn_agent.NATURE_DQN_STACK_SIZE
      self.env_batch_size = 4
  
      self.zero_state = np.zeros(
          [
              self.env_batch_size,
              self.observation_shape[0],
              self.observation_shape[1],
              self.stack_size,
          ]
      )
  
file_path: tensor2tensor/tensor2tensor/rl/batch_dqn_agent_test.py
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import os
  import shutil
  from absl import flags
  from dopamine.agents.dqn import dqn_agent
  from dopamine.discrete_domains import atari_lib
  import numpy
  from tensor2tensor.rl import dopamine_connector
  import tensorflow.compat.v1
label_desc: Use image node_id 1 for calling the BatchDQNAgentTest obj's underlying member method code with example usage: obj.setUp() without return types