code: def test_is_model_wrapper_and_persistent_workers_on(
      self, mock_is_model_wrapper
  ):
      mock_is_model_wrapper.return_value = True
      runner = Mock()
      runner.model = Mock()
      runner.model.module = Mock()
      runner.model.module.detector.bbox_head.use_l1 = False
      runner.train_dataloader = Mock()
      runner.train_dataloader.persistent_workers = True
      runner.train_dataloader._DataLoader__initialized = True
      runner.epoch = 284
      runner.max_epochs = 300
  
      hook = YOLOXModeSwitchHook(num_last_epochs=15)
      hook.before_train_epoch(runner)
      self.assertTrue(hook._restart_dataloader)
      self.assertTrue(runner.model.module.detector.bbox_head.use_l1)
      self.assertFalse(runner.train_dataloader._DataLoader__initialized)
  
      runner.epoch = 285
      hook.before_train_epoch(runner)
      self.assertTrue(runner.train_dataloader._DataLoader__initialized)
  
file_path: mmdetection/tests/test_engine/test_hooks/test_yolox_mode_switch_hook.py
imports: from unittest import TestCase
  from unittest.mock import Mock, patch
  from mmdet.engine.hooks import YOLOXModeSwitchHook
label_desc: Use image node_id 1 for calling the TestYOLOXModeSwitchHook obj's underlying member method code with example usage: obj.test_is_model_wrapper_and_persistent_workers_on(mock_is_model_wrapper) without return types