code: def test_contrast(self):
      enhancement_amount = 80.0
  
      data, path = self.get_whitenoise()
      result = F.contrast(data, enhancement_amount)
      self.assert_sox_effect(
          result, path, ["contrast", enhancement_amount]
      )
  
imports: import torch
  import torchaudio.functional
  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 19 for calling the TestFunctionalFiltering obj's underlying member method code with example usage: obj.test_contrast() without return types