code: def add_batch_dim(spec, outer_dims):
      return tf.TensorSpec(
          shape=tf.TensorShape(outer_dims).concatenate(spec.shape),
          name=spec.name,
          dtype=spec.dtype,
      )
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import copy
  import functools
  import os
  from typing import Any, Callable, Dict, Tuple, Optional, Text, cast, Sequence
  from absl import logging
  import tensorflow
  import tensorflow_probability
  from tf_agents.policies import tf_policy
  from tf_agents.specs import tensor_spec
  from tf_agents.trajectories import time_step
  from tf_agents.typing import types
  from tf_agents.utils import common
  from tf_agents.utils import nest_utils
  from tensorflow.python.eager import def_function
label_desc: Use image node_id 5 for calling a global function with example usage: add_batch_dim(spec, outer_dims) and returns: tf