code: def drop_arm_observation(
      trajectory: types.Trajectory,
  ) -> types.Trajectory:
      """Drops the per-arm observation from a given trajectory/trajectory spec."""
      transformed_trajectory = copy.deepcopy(trajectory)
      del transformed_trajectory.observation[PER_ARM_FEATURE_KEY]
      return transformed_trajectory
  
file_path: agents/tf_agents/specs/bandit_spec_utils.py
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import copy
  from typing import Optional, Tuple
  import tensorflow
  from tf_agents.specs import tensor_spec
  from tf_agents.typing import types
label_desc: Use image node_id 3 for calling a global function with example usage: drop_arm_observation(trajectory) and returns: transformed_trajectory