code: def test_step(self):
      frame_shape = (84, 84, 4)
      game = self.choose_random_game()
      env = env_utils.create_env(game, clip_rewards=True)
      obs = env.reset()
      actions = [1, 2, 3, 0]
      for a in actions:
          obs, reward, done, info = env.step(a)
          self.assertEqual(obs.shape, frame_shape)
          self.assertTrue(reward <= 1.0 and reward >= -1.0)
          self.assertTrue(isinstance(done, bool))
          self.assertTrue(isinstance(info, dict))
  
imports: from absl.testing import absltest
  from flax.training import train_state
  import jax
  import ml_collections
  import numpy
  import numpy.testing
  import agent
  import env_utils
  import models
  import ppo_lib
label_desc: Use image node_id 3 for calling the TestEnvironmentPreprocessing obj's underlying member method code with example usage: obj.test_step() without return types