code: def _get_tpu_strategy():
      if not tf.config.list_logical_devices("TPU"):
          logging.info(
              "TPU hardware is not available, TPU strategy test skipped."
          )
          return None
  
      resolver = tf.distribute.cluster_resolver.TPUClusterResolver("")
      tf.config.experimental_connect_to_cluster(resolver)
      tf.tpu.experimental.initialize_tpu_system(resolver)
      return tf.distribute.experimental.TPUStrategy(resolver)
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import functools
  import os
  from absl import logging
  from absl.testing import parameterized
  import numpy
  from six.moves import range
  import tensorflow
  from tf_agents.agents.behavioral_cloning import behavioral_cloning_agent
  from tf_agents.environments import suite_gym
  from tf_agents.environments import tf_py_environment
  from tf_agents.keras_layers import inner_reshape
  from tf_agents.networks import sequential
  from tf_agents.specs import tensor_spec
  from tf_agents.system import system_multiprocessing
  from tf_agents.train import learner
  from tf_agents.train.utils import test_utils
  from tf_agents.train.utils import train_utils
  from tf_agents.trajectories import time_step
  from tf_agents.utils import common
  from tf_agents.utils import test_utils
label_desc: Use image node_id 2 for calling a global function with example usage: _get_tpu_strategy() and returns: tf, None