code: def setUpClass(cls):
      cls.root_dir = cls.get_base_temp_dir()
      (
          cls.samples_10min,
          cls.samples_1h,
          cls.samples_10h,
      ) = get_mock_datasets(cls.root_dir)
  
file_path: audio/test/torchaudio_unittest/datasets/librilightlimited_test.py
imports: import os
  from torchaudio.datasets import librilight_limited
  from torchaudio_unittest.common_utils import get_whitenoise, save_wav, TempDirMixin, TorchaudioTestCase
label_desc: Use image node_id 1 for calling the TestLibriLightLimited obj's underlying member method code with example usage: obj.setUpClass(cls) without return types