code: def test_vol(self, gain_type, gain):
      data, path = self.get_whitenoise()
      result = T.Vol(gain, gain_type)(data)
      self.assert_sox_effect(
          result, path, ["vol", f"{gain}", gain_type]
      )
  
file_path: audio/test/torchaudio_unittest/transforms/sox_compatibility_test.py
imports: import warnings
  import torch
  import torchaudio.transforms
  from parameterized import parameterized
  from torchaudio_unittest.common_utils import get_asset_path, get_whitenoise, load_wav, save_wav, skipIfNoExec, skipIfNoSox, sox_utils, TempDirMixin, TorchaudioTestCase
label_desc: Use image node_id 5 for calling the TestFunctionalFiltering obj's underlying member method code with example usage: obj.test_vol(gain_type, gain) without return types