code: def setUp(self):
      super(ReverbReplayBufferTest, self).setUp()
  
      # Prepare the environment (and the corresponding specs).
      self._env = test_envs.EpisodeCountingEnv(steps_per_episode=3)
      tensor_time_step_spec = tf.nest.map_structure(
          tensor_spec.from_spec, self._env.time_step_spec()
      )
      tensor_action_spec = tensor_spec.from_spec(
          self._env.action_spec()
      )
      self._data_spec = trajectory.Trajectory(
          step_type=tensor_time_step_spec.step_type,
          observation=tensor_time_step_spec.observation,
          action=tensor_action_spec,
          policy_info=(),
          next_step_type=tensor_time_step_spec.step_type,
          reward=tensor_time_step_spec.reward,
          discount=tensor_time_step_spec.discount,
      )
      # TODO(b/188427258) Add time dimension when using Reverb.TrajectoryWriters.
      # table_signature = tensor_spec.add_outer_dim(self._data_spec)
      self._array_data_spec = tensor_spec.to_nest_array_spec(
          self._data_spec
      )
  
      # Initialize and start a Reverb server (and set up a client to it).
      self._table_name = "test_table"
      uniform_table = reverb.Table(
          self._table_name,
          max_size=100,
          sampler=reverb.selectors.Uniform(),
          remover=reverb.selectors.Fifo(),
          rate_limiter=reverb.rate_limiters.MinSize(1),
          # signature=table_signature,
      )
      self._server = reverb.Server([uniform_table])
      self._py_client = reverb.Client(
          "localhost:{}".format(self._server.port)
      )
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  from absl.testing import parameterized
  import reverb
  import tensorflow
  from tf_agents.drivers import py_driver
  from tf_agents.environments import test_envs
  from tf_agents.policies import random_py_policy
  from tf_agents.replay_buffers import reverb_replay_buffer
  from tf_agents.replay_buffers import reverb_utils
  from tf_agents.specs import array_spec
  from tf_agents.specs import tensor_spec
  from tf_agents.trajectories import trajectory
  from tf_agents.utils import common
  from tf_agents.utils import test_utils
label_desc: Use image node_id 1 for calling the ReverbReplayBufferTest obj's underlying member method code with example usage: obj.setUp() without return types