class_docstr: Test environment.
  
  Odd frames are "done".
class_docstr_tok: ["Test","environment",".","Odd","frames","are","``","done","''","."]
code: def _generate_ob(self):
      return self.observation_space.sample()
  
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 2 for calling the TestEnv obj's underlying member method code with example usage: obj._generate_ob() and returns: self