code: def assert_channels(self, env, obs, n_channels):
      self.assertEqual(env.observation_space.shape[2], n_channels)
      self.assertEqual(env.num_channels, n_channels)
      for obs_batch in obs:
          ob = obs_batch[0]
          self.assertEqual(ob.shape[2], n_channels)
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import os
  import shutil
  import gym
  from gym.spaces import Box
  from gym.spaces import Discrete
  import numpy
  from tensor2tensor.data_generators import gym_env
  from tensor2tensor.data_generators import problem
  from tensor2tensor.rl.gym_utils import make_gym_env
  import tensorflow.compat.v1
label_desc: Use image node_id 13 for calling the GymEnvTest obj's underlying member method code with example usage: obj.assert_channels(env, obs, n_channels) without return types