code: def test_grayscale_step(self):
      self.env.reset()
      self.env_g.reset()
      obs, _, _, _ = self.env.step(1)
      obs_g, _, _, _ = self.env_g.step(1)
  
      grayscale_output = np.round(
          np.dot(obs[:, :, :3], [0.2125, 0.7154, 0.0721])
      ).astype(np.uint8)
      np.testing.assert_array_almost_equal(grayscale_output, obs_g)
  
file_path: garage/tests/garage/envs/wrappers/test_grayscale_env.py
imports: import gym.spaces
  import numpy
  import pytest
  from garage.envs.wrappers import Grayscale
  from tests.fixtures.envs.dummy import DummyDiscretePixelEnv
label_desc: Use image node_id 7 for calling the TestGrayscale obj's underlying member method code with example usage: obj.test_grayscale_step() without return types