code: def setUp(self):
      super(DQNAgentTest, 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.observation_dtype = jnp.uint8
      self.stack_size = dqn_agent.NATURE_DQN_STACK_SIZE
      self.zero_state = onp.zeros(
          self.observation_shape + (self.stack_size,)
      )
      gin.bind_parameter("OutOfGraphReplayBuffer.replay_capacity", 100)
      gin.bind_parameter("OutOfGraphReplayBuffer.batch_size", 2)
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import os
  import shutil
  from absl import flags
  from absl.testing import absltest
  from dopamine.discrete_domains import atari_lib
  from dopamine.jax.agents.dqn import dqn_agent
  from dopamine.utils import test_utils
  from flax import linen
  import gin
  import jax.numpy
  import mock
  import numpy
label_desc: Use image node_id 1 for calling the DQNAgentTest obj's underlying member method code with example usage: obj.setUp() without return types