code: def test_call(self):
      trajectories = []
  
      def observer(traj):
          trajectories.append(traj)
  
      def observer_fn():
          return observer
  
      unbatcher = batched_observer_unbatching.BatchedObserverUnbatching(
          observer_fn, batch_size=2
      )
  
      trajectory = trajectory_lib.Trajectory(
          action=tf.constant([0, 1]),
          discount=tf.constant([0, 0]),
          next_step_type=tf.constant([1, 2]),
          observation={
              "a": tf.constant([24, 42]),
              "b": tf.constant([100, 200]),
          },
          policy_info=tf.constant([500, 1000]),
          reward=tf.constant([25, 50]),
          step_type=tf.constant([13, 26]),
      )
      unbatcher(trajectory)
  
      self.assertEqual(
          trajectories,
          [
              trajectory_lib.Trajectory(
                  action=tf.constant([0]),
                  discount=tf.constant([0]),
                  next_step_type=tf.constant([1]),
                  observation={
                      "a": tf.constant([24]),
                      "b": tf.constant([100]),
                  },
                  policy_info=tf.constant([500]),
                  reward=tf.constant([25]),
                  step_type=tf.constant([13]),
              ),
              trajectory_lib.Trajectory(
                  action=tf.constant([1]),
                  discount=tf.constant([0]),
                  next_step_type=tf.constant([2]),
                  observation={
                      "a": tf.constant([42]),
                      "b": tf.constant([200]),
                  },
                  policy_info=tf.constant([1000]),
                  reward=tf.constant([50]),
                  step_type=tf.constant([26]),
              ),
          ],
      )
  
file_path: agents/tf_agents/utils/batched_observer_unbatching_test.py
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import reverb
  import tensorflow
  from tf_agents.drivers import py_driver
  from tf_agents.environments import parallel_py_environment
  from tf_agents.environments import suite_gym
  from tf_agents.policies import random_py_policy
  from tf_agents.replay_buffers import reverb_utils
  from tf_agents.specs import tensor_spec
  from tf_agents.trajectories import trajectory
  from tf_agents.utils import batched_observer_unbatching
label_desc: Use image node_id 1 for calling the BatchedObserverUnbatchingTest obj's underlying member method code with example usage: obj.test_call() and returns: observer