class_docstr: Test environment.
  
  Odd frames are "done".
class_docstr_tok: ["Test","environment",".","Odd","frames","are","``","done","''","."]
code: def step(self, action):
      done = self._counter % 2 == 1
      self._counter += 1
      reward = 5 if done else -5
      return (self._generate_ob(), reward, done, {})
  
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 3 for calling the TestEnv obj's underlying member method code with example usage: obj.step(action) and returns: self,  reward,  done,  dict