code: def testIsolation(self, isolation):
      py_env = self._get_py_env(batch_py_env=False, isolation=isolation)
      tf_env = tf_py_environment.TFPyEnvironment(
          py_env, isolation=isolation
      )
      last_env_thread = lambda: get(tf_env.pyenv, "last_call_thread_id")
      local_thread = threading.current_thread().ident
      if isolation:
          self.assertNotEqual(local_thread, last_env_thread())
      else:
          self.assertEqual(local_thread, last_env_thread())
  
      # The remaining tests apply only to isolation == True
      if not isolation:
          return
  
      init_env_thread = last_env_thread()
      # Ensure that parallel computation does run in a thread different from the
      # one the pyenv was initialized in: that isolation forced execution on a
      # single dedicated threadpool.
      for _ in range(30):
          self.evaluate([tf_env.reset() for _ in range(16)])
          self.assertEqual(init_env_thread, last_env_thread())
          self.evaluate([tf_env.current_time_step() for _ in range(16)])
          self.assertEqual(init_env_thread, last_env_thread())
          self.evaluate(
              [tf_env.step(tf.constant([1])) for _ in range(16)]
          )
          self.assertEqual(init_env_thread, last_env_thread())
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import threading
  from typing import Text
  from absl.testing import parameterized
  from absl.testing.absltest import mock
  import numpy
  import tensorflow
  from tf_agents import specs
  from tf_agents.environments import batched_py_environment
  from tf_agents.environments import py_environment
  from tf_agents.environments import suite_gym
  from tf_agents.environments import tf_py_environment
  from tf_agents.trajectories import time_step
  from tf_agents.utils import common
label_desc: Use image node_id 14 for calling the TFPYEnvironmentTest obj's underlying member method code with example usage: obj.testIsolation(isolation) without return types