code: def test_sync_many_files_local_to_cloud(mock_s3_bucket_uri, tmp_path):
      source_dir = tmp_path / "source"
      check_dir = tmp_path / "check"
      source_dir.mkdir()
      check_dir.mkdir()
  
      # Create 256 files to upload
      for i in range(256):
          (source_dir / str(i)).write_text("", encoding="utf-8")
  
      fs, fs_path = get_fs_and_path(mock_s3_bucket_uri)
      _upload_to_fs_path(source_dir, fs, fs_path)
      _download_from_fs_path(fs, fs_path, check_dir)
      assert (check_dir / "255").exists()
  
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 19 for calling a global function with example usage: test_sync_many_files_local_to_cloud(mock_s3_bucket_uri, tmp_path) without return types