code: def tearDownClass(cls):
      super().tearDownClass()
      COMMONVOICE._ext_audio = _ORIGINAL_EXT_AUDIO
  
imports: import csv
  import os
  from pathlib import Path
  from typing import Dict, Tuple
  from torch import Tensor
  from torchaudio.datasets import COMMONVOICE
  from torchaudio_unittest.common_utils import get_whitenoise, normalize_wav, save_wav, TempDirMixin, TorchaudioTestCase
label_desc: Use image node_id 2 for calling the BaseTestCommonVoice obj's underlying member method code with example usage: obj.tearDownClass(cls) without return types