code: def _choose_next_state(self):
      self.state = self.observation_space.sample()
  
imports: import collections
  import functools
  import itertools
  import multiprocessing
  import pytest
  import gym
  import numpy
  from stable_baselines.common.vec_env import DummyVecEnv, SubprocVecEnv, VecNormalize, VecFrameStack
label_desc: Use image node_id 4 for calling the CustomGymEnv obj's underlying member method code with example usage: obj._choose_next_state() without return types