code: def setup_method(self):
      self.n_frames = 4
      self.env = DummyDiscrete2DEnv(random=False)
      self.env_s = StackFrames(
          DummyDiscrete2DEnv(random=False), n_frames=self.n_frames
      )
      self.width, self.height = self.env.observation_space.shape
  
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 1 for calling the TestStackFrames obj's underlying member method code with example usage: obj.setup_method() without return types