code: def test_syncer_serialize(temp_data_dirs, syncer):
      tmp_source, tmp_target = temp_data_dirs
  
      syncer.sync_up(local_dir=tmp_source, remote_dir="/test/serialize")
  
      serialized = pickle.dumps(syncer)
      loaded_syncer = pickle.loads(serialized)
      assert not loaded_syncer._sync_process
  
imports: import logging
  import os
  import time
  from typing import List, Optional
  from freezegun import freeze_time
  import pytest
  import ray
  import ray.cloudpickle
  from ray.train._internal.storage import _upload_to_fs_path, _download_from_fs_path, get_fs_and_path, _FilesystemSyncer
  from ray.train._internal.syncer import _BackgroundProcess
  from ray.train.tests.test_new_persistence import _create_mock_custom_fs
label_desc: Use image node_id 18 for calling a global function with example usage: test_syncer_serialize(temp_data_dirs, syncer) without return types