code: def test_dirwatcher_update_policy_live_calls_file_changed_iff_file_nonempty(
      tempdir: Path,
      file_pusher: FilePusher,
      dir_watcher: DirWatcher,
      write_file: Callable[[Path], None],
      expect_called: bool,
  ):
      """Test that if a file exists, the update policy is called."""
      f = tempdir / "my-file.txt"
      write_file(f)
      dir_watcher.update_policy(str(f), "live")
      assert file_pusher.file_changed.called == expect_called
  
imports: import os
  import tempfile
  import time
  from pathlib import Path
  from typing import TYPE_CHECKING, Callable
  from unittest.mock import Mock, patch
  import pytest
  import wandb.filesync.dir_watcher
  from wandb.filesync.dir_watcher import DirWatcher, PolicyEnd, PolicyLive, PolicyNow
  from wandb.sdk.internal.file_pusher import FilePusher
label_desc: Use image node_id 6 for calling a global function with example usage: test_dirwatcher_update_policy_live_calls_file_changed_iff_file_nonempty(tempdir, file_pusher, dir_watcher, write_file, expect_called) without return types