code: def get_ob_rms(env):
      """get ob_rms value from current env, if current env does not wrap VecNormalizeEnv, None will be returned
      Args:
          env (gym.Wrapper): current env
      """
      vec_norm_env = get_wrapper_by_cls(env, VecNormalizeEnv)
      ob_rms = None
      if vec_norm_env:
          ob_rms = vec_norm_env.get_ob_rms()
  
      return ob_rms
  
imports: import numpy
  import gym
  import time
  from parl.env.compat_wrappers import CompatWrapper
label_desc: Use image node_id 3 for calling a global function with example usage: get_ob_rms(env) and returns: ob_rms