code: def _update_filter(self):
      # getting the filter sync.
      # Collect filters from  all actors and update global filter
      future_object_ids = [
          remote_actor.get_filter(flush_after=True)
          for remote_actor in self.remote_actors
      ]
      filters = [
          future_object.get() for future_object in future_object_ids
      ]
      for actor_filter in filters:
          self.obs_filter.apply_changes(actor_filter)
  
      #  set_filter of all actors
      self.latest_obs_filter = self.obs_filter.as_serializable()
      [
          remote_actor.set_filter(self.latest_obs_filter)
          for remote_actor in self.remote_actors
      ]
  
imports: import time
  import gym
  import parl
  import numpy
  import utils
  from es import ES
  from obs_filter import MeanStdFilter
  from mujoco_agent import MujocoAgent
  from mujoco_model import MujocoModel
  from noise import SharedNoiseTable
  from parl.utils import logger, summary
  from parl.env import CompatWrapper
  from parl.utils.window_stat import WindowStat
  from actor import Actor
label_desc: Use image node_id 4 for calling the Learner obj's underlying member method code with example usage: obj._update_filter() without return types