code: def test_wandb_pickle(wandb_mock, tmp_path):
      """Verify that pickling trainer with wandb logger works.
  
      Wandb doesn't work well with pytest so we have to mock it out here.
  
      """
  
      class Experiment:
          id = "the_id"
          step = 0
          dir = "wandb"
  
          @property
          def name(self):
              return "the_run_name"
  
      wandb_mock.wandb_run = Experiment
  
      wandb_mock.run = None
      wandb_mock.init.return_value = Experiment()
      logger = WandbLogger(id="the_id", offline=True)
  
      trainer = Trainer(
          default_root_dir=tmp_path, max_epochs=1, logger=logger
      )
      # Access the experiment to ensure it's created
      assert trainer.logger.experiment, "missing experiment"
      assert trainer.log_dir == logger.save_dir
      pkl_bytes = pickle.dumps(trainer)
      trainer2 = pickle.loads(pkl_bytes)
  
      assert os.environ["WANDB_MODE"] == "dryrun"
      assert trainer2.logger.__class__.__name__ == WandbLogger.__name__
      assert trainer2.logger.experiment, "missing experiment"
  
      wandb_mock.init.assert_called()
      assert "id" in wandb_mock.init.call_args[1]
      assert wandb_mock.init.call_args[1]["id"] == "the_id"
  
      del os.environ["WANDB_MODE"]
  
imports: import os
  import pickle
  from unittest import mock
  import pytest
  import yaml
  from lightning.pytorch import Trainer
  from lightning.pytorch.callbacks import ModelCheckpoint
  from lightning.pytorch.cli import LightningCLI
  from lightning.pytorch.demos.boring_classes import BoringModel
  from lightning.pytorch.loggers import WandbLogger
  from lightning.pytorch.utilities.exceptions import MisconfigurationException
  from lightning_utilities.test.warning import no_warning_call
label_desc: Use image node_id 4 for calling a global function with example usage: test_wandb_pickle(wandb_mock, tmp_path) and returns: str