code: def _restore_and_log_checkpoint(self, actor):
          
          actor_id = self._worker.actor_id
          try:
              checkpoints = ray.actor.get_checkpoints_for_actor(actor_id)
              if len(checkpoints) > 0:
                  # If we found previously saved checkpoints for this actor,
                  # call the `load_checkpoint` callback.
                  checkpoint_id = actor.load_checkpoint(actor_id, checkpoints)
                  if checkpoint_id is not None:
                      # Check that the returned checkpoint id is in the
                      # `available_checkpoints` list.
                      msg = (
                          "`load_checkpoint` must return a checkpoint id that " +
                          "exists in the `available_checkpoints` list, or eone.")
                      assert any(checkpoint_id == checkpoint.checkpoint_id
                                 for checkpoint in checkpoints), msg
                      # Notify raylet that this actor has been resumed from
                      # a checkpoint.
                      (self._worker.raylet_client.
                       notify_actor_resumed_from_checkpoint(
                           actor_id, checkpoint_id))
          except Exception:
              # Checkpoint save or reload failed. Notify the driver.
              traceback_str = ray.utils.format_error_message(
                  traceback.format_exc())
              ray.utils.push_error_to_driver(
                  self._worker,
                  ray_constants.CHECKPOINT_PUSH_ERROR,
                  traceback_str,
                  driver_id=self._worker.task_driver_id)
docs: Restore an actor from a checkpoint if available and log any errors.
  
          This should only be called on workers that have just executed an actor
          creation task.
  
          Args:
              actor: The actor to restore from a checkpoint.