code: def test_trajectory_batch_stream_shape(self):
      task = rl_task.RLTask(
          DummyEnv(), initial_trajectories=1, max_steps=10
      )
      batch_stream = task.trajectory_batch_stream(
          batch_size=3, min_slice_length=4, max_slice_length=4
      )
      batch = next(batch_stream)
      self.assertEqual(batch.observation.shape, (3, 4, 2))
  
imports: import os
  from absl.testing import absltest
  import gym
  import numpy
  from trax import test_utils
  from trax.rl import task
label_desc: Use image node_id 27 for calling the TaskTest obj's underlying member method code with example usage: obj.test_trajectory_batch_stream_shape() without return types