code: def testFirstTimeStep(self, batch_py_env, isolation):
      py_env = self._get_py_env(batch_py_env, isolation)
      tf_env = tf_py_environment.TFPyEnvironment(
          py_env, isolation=isolation
      )
      time_step = tf_env.current_time_step()
      time_step = self.evaluate(time_step)
      self.assertAllEqual([ts.StepType.FIRST], time_step.step_type)
      self.assertAllEqual([0.0], time_step.reward)
      self.assertAllEqual([1.0], time_step.discount)
      self.assertAllEqual([0], time_step.observation)
      self.assertAllEqual([], get(tf_env.pyenv, "actions_taken"))
      self.assertEqual(1, get(tf_env.pyenv, "resets"))
      self.assertEqual(0, get(tf_env.pyenv, "steps"))
      self.assertEqual(0, get(tf_env.pyenv, "episodes"))
  
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 9 for calling the TFPYEnvironmentTest obj's underlying member method code with example usage: obj.testFirstTimeStep(batch_py_env, isolation) without return types