code: def test_auto_add_dataloader_idx(tmpdir, add_dataloader_idx):
      """Test that auto_add_dataloader_idx argument works."""
  
      class TestModel(BoringModel):
          def val_dataloader(self):
              dl = super().val_dataloader()
              return [dl, dl]
  
          def validation_step(self, *args, **kwargs):
              output = super().validation_step(*args[:-1], **kwargs)
              name = (
                  "val_loss"
                  if add_dataloader_idx
                  else f"val_loss_custom_naming_{args[-1]}"
              )
  
              self.log(
                  name,
                  output["x"],
                  add_dataloader_idx=add_dataloader_idx,
              )
              return output
  
      model = TestModel()
  
      trainer = Trainer(default_root_dir=tmpdir, fast_dev_run=2)
      trainer.fit(model)
      logged = trainer.logged_metrics
  
      # Check that the correct keys exist
      if add_dataloader_idx:
          assert "val_loss/dataloader_idx_0" in logged
          assert "val_loss/dataloader_idx_1" in logged
      else:
          assert "val_loss_custom_naming_0" in logged
          assert "val_loss_custom_naming_1" in logged
  
imports: import operator
  from functools import partial
  from unittest import mock
  from unittest.mock import Mock
  import pytest
  import torch
  from lightning.pytorch import LightningModule
  from lightning.pytorch.callbacks.callback import Callback
  from lightning.pytorch.demos.boring_classes import BoringModel, RandomDataset
  from lightning.pytorch.loggers import CSVLogger
  from lightning.pytorch.trainer import Trainer
  from lightning.pytorch.trainer.connectors.logger_connector.fx_validator import _FxValidator
  from lightning.pytorch.trainer.connectors.logger_connector.result import _ResultCollection
  from lightning.pytorch.utilities.exceptions import MisconfigurationException
  from lightning.pytorch.utilities.imports import _TORCHMETRICS_GREATER_EQUAL_0_9_1
  from lightning.pytorch.utilities.imports import _TORCHMETRICS_GREATER_EQUAL_0_11
  from lightning_utilities.core.imports import compare_version
  from torch.utils.data import DataLoader
  from torchmetrics import Accuracy, MeanAbsoluteError, MeanSquaredError, MetricCollection
  from torchmetrics import AveragePrecision
  from tests_pytorch.models.test_hooks import get_members
label_desc: Use image node_id 3 for calling a global function with example usage: test_auto_add_dataloader_idx(tmpdir, add_dataloader_idx) and returns: list, output