code: def test_observer_writes_multi_tables(self):
      episode_length = 3
      collect_step_count = 6
      table_count = 2
      create_observer_fn = _create_add_sequence_observer_fn(
          table_name=["test_table1", "test_table2"],
          sequence_length=episode_length,
          stride_length=episode_length,
      )
      env = _env_creator(episode_length)()
      with create_observer_fn(self._mock_client) as observer:
          policy = _create_random_policy_from_env(env)
          driver = py_driver.PyDriver(
              env,
              policy,
              observers=[observer],
              max_steps=collect_step_count,
          )
          driver.run(env.reset())
  
      self.assertEqual(
          table_count * int(collect_step_count / episode_length),
          self._mock_writer.create_item.call_count,
      )
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import contextlib
  import functools
  import time
  from absl.testing import parameterized
  import mock
  import reverb
  from six.moves import range
  import tensorflow
  from tf_agents.drivers import py_driver
  from tf_agents.environments import parallel_py_environment
  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 tensor_spec
  from tf_agents.system import system_multiprocessing
  from tf_agents.trajectories import time_step
  from tf_agents.utils import test_utils
label_desc: Use image node_id 4 for calling the ReverbObserverTest obj's underlying member method code with example usage: obj.test_observer_writes_multi_tables() without return types