docstr: Save the filter's internal state to a checkpoint to file, so that it can be later restored.
  :param checkpoint_dir: the directory from which to restore
  :param checkpoint_prefix: the checkpoint prefix to look for
  :return: None
code: def restore_state_from_checkpoint(
      self, checkpoint_dir, checkpoint_prefix
  ) -> None:
      """
      Save the filter's internal state to a checkpoint to file, so that it can be later restored.
      :param checkpoint_dir: the directory from which to restore
      :param checkpoint_prefix: the checkpoint prefix to look for
      :return: None
      """
      pass
  
imports: import copy
  import os
  from collections import OrderedDict
  from copy import deepcopy
  from typing import Dict, Union, List
  from rl_coach.core_types import EnvResponse, ActionInfo, Transition
  from rl_coach.spaces import ActionSpace, RewardSpace, ObservationSpace
  from rl_coach.utils import force_list
label_desc: Use image node_id 7 for calling the Filter obj's underlying member method code with example usage: obj.restore_state_from_checkpoint(checkpoint_dir, checkpoint_prefix) without return types