code: def test_stack_frames_for_step(self):
      self.env.reset()
      self.env_s.reset()
  
      frame_stack = np.empty((self.width, self.height, self.n_frames))
      for _ in range(10):
          frame_stack = frame_stack[:, :, 1:]
          obs, _, _, _ = self.env.step(1)
          frame_stack = np.dstack((frame_stack, obs))
          obs_stack, _, _, _ = self.env_s.step(1)
  
      np.testing.assert_array_equal(obs_stack, frame_stack)
  
file_path: garage/tests/garage/envs/wrappers/test_stack_frames_env.py
imports: import gym.spaces
  import numpy
  import pytest
  from garage.envs.wrappers import StackFrames
  from tests.fixtures.envs.dummy import DummyDiscrete2DEnv
label_desc: Use image node_id 7 for calling the TestStackFrames obj's underlying member method code with example usage: obj.test_stack_frames_for_step() without return types