code: def setup_watch_mock(
      self, watch_return: set[FileChange]
  ) -> MagicMock:
      # changes: 1 -> added, 2 -> modified, 3 -> deleted
      patcher = patch(f"{ServiceReloaderPlugin.__module__}.watch")
      watch_mock = patcher.start()
      self.addCleanup(patcher.stop)
      # return value {(<Change.added: 1>, 'path/to/file.txt'), ...}
      watch_mock.return_value = iter([watch_return])  # type: ignore
      return watch_mock
  
imports: from __future__ import annotations
  import logging
  import os
  import typing
  from pathlib import Path
  from typing import TYPE_CHECKING
  from unittest import skipUnless
  from unittest.mock import patch
  import pytest
  from circus.tests.support import TestCircus
  from bentoml._internal.utils.circus.watchfilesplugin import ServiceReloaderPlugin
  from bentoml._internal.utils.pkg import source_locations
label_desc: Use image node_id 7 for calling the TestServiceReloaderPlugin obj's underlying member method code with example usage: obj.setup_watch_mock(watch_return) and returns: watch_mock