code: def test_flatten(self):
      for _ in range(10):
          self.env.reset()
          self.env.visualize()
          for _ in range(5):
              action = self.env.action_space.sample()
              es = self.env.step(action)
              next_obs, done = es.observation, es.terminal
              assert (
                  next_obs.shape == self.env.observation_space.low.shape
              )
              if done:
                  break
  
imports: from garage.envs import GymEnv, normalize
label_desc: Use image node_id 4 for calling the TestNormalizedGym obj's underlying member method code with example usage: obj.test_flatten() without return types