code: def test_warning_raised_on_deprecation():
      with warnings.catch_warnings(record=True) as w:
          al = ActiveLearningDataset(MyDataset())
          _ = al._labelled
          assert len(w) == 1
          assert w[0].category is DeprecationWarning
  
imports: import pickle
  import unittest
  import unittest.mock
  import warnings
  import datasets
  import numpy
  import pytest
  import torch.utils.data
  from torchvision.transforms import Lambda
  from baal.active import ActiveLearningDataset
label_desc: Use image node_id 4 for calling a global function with example usage: test_warning_raised_on_deprecation() without return types