code: def test_picklable_datasets(test_data):
      # Test that the datasets are picklable.
      X = test_data["X"]
      for dataset in [
          test_data["contiguous_dataset"],
          test_data["dataset_csr"],
          test_data["fortran_dataset"],
          test_data["dataset_csc"],
      ]:
          pds = pickle.dumps(dataset)
          dataset = pickle.loads(pds)
          assert dataset.get_n_samples() == X.shape[0]
          assert dataset.get_n_features() == X.shape[1]
  
file_path: lightning/lightning/impl/tests/test_dataset.py
imports: import pickle
  import numpy
  import pytest
  import scipy.sparse
  from sklearn.datasets import make_classification
  from sklearn.utils import check_random_state
  from lightning.impl.dataset_fast import ContiguousDataset
  from lightning.impl.dataset_fast import FortranDataset
  from lightning.impl.dataset_fast import CSRDataset
  from lightning.impl.dataset_fast import CSCDataset
label_desc: Use image node_id 6 for calling a global function with example usage: test_picklable_datasets(test_data) without return types