code: def unwrap_vec_normalize(
      env: Union[gym.Env, VecEnv]
  ) -> Union[VecNormalize, None]:
      """
      :param env: (Union[gym.Env, VecEnv])
      :return: (VecNormalize)
      """
      env_tmp = env
      while isinstance(env_tmp, VecEnvWrapper):
          if isinstance(env_tmp, VecNormalize):
              return env_tmp
          env_tmp = env_tmp.venv
      return None
  
file_path: stable-baselines/stable_baselines/common/vec_env/__init__.py
imports: from typing import Union
  from copy import deepcopy
  import gym
  from stable_baselines.common.vec_env.base_vec_env import AlreadySteppingError, NotSteppingError, VecEnv, VecEnvWrapper, CloudpickleWrapper
  from stable_baselines.common.vec_env.dummy_vec_env import DummyVecEnv
  from stable_baselines.common.vec_env.subproc_vec_env import SubprocVecEnv
  from stable_baselines.common.vec_env.vec_frame_stack import VecFrameStack
  from stable_baselines.common.vec_env.vec_normalize import VecNormalize
  from stable_baselines.common.vec_env.vec_video_recorder import VecVideoRecorder
  from stable_baselines.common.vec_env.vec_check_nan import VecCheckNan
label_desc: Use image node_id 1 for calling a global function with example usage: unwrap_vec_normalize(env) and returns: None, env_tmp