code: def setUpClass(cls):
      cls.root_dir = cls.get_base_temp_dir()
      dataset_dir = os.path.join(
          cls.root_dir,
          speechcommands.FOLDER_IN_ARCHIVE,
          speechcommands.URL,
      )
      (
          cls.samples,
          cls.train_samples,
          cls.valid_samples,
          cls.test_samples,
      ) = get_mock_dataset(dataset_dir)
  
file_path: audio/test/torchaudio_unittest/datasets/speechcommands_test.py
imports: import os
  from pathlib import Path
  from torchaudio.datasets import speechcommands
  from torchaudio_unittest.common_utils import get_whitenoise, normalize_wav, save_wav, TempDirMixin, TorchaudioTestCase
label_desc: Use image node_id 1 for calling the TestSpeechCommands obj's underlying member method code with example usage: obj.setUpClass(cls) without return types