code: def get_model_index(
      arm_index: int, accepts_per_arm_features: bool
  ) -> int:
      """Returns the model index for a specific arm.
  
      The number of models depends on the observation format: If the policy accepts
      per-arm features, there is only one single model used for every arm. Otherwise
      there is a model for every arm.
  
      Args:
        arm_index: The index of the arm for which the model index is needed.
        accepts_per_arm_features: (bool) Whether the policy works with per-arm
          features.
  
      Returns:
        The index of the model for the arm requested.
      """
      return 0 if accepts_per_arm_features else arm_index
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import collections
  from typing import Optional, Sequence, Text, Union
  import tensorflow
  from tf_agents.specs import bandit_spec_utils
  from tf_agents.specs import tensor_spec
  from tf_agents.trajectories import policy_step
  from tf_agents.typing import types
  from tf_agents.utils import common
label_desc: Use image node_id 9 for calling a global function with example usage: get_model_index(arm_index, accepts_per_arm_features) and returns: unknown