code: def test_melscale(self):
      sample_rate = 8000
      n_fft = 400
      n_stft = n_fft // 2 + 1
      n_mels = 128
      transform = T.MelScale(
          sample_rate=sample_rate, n_mels=n_mels, n_stft=n_stft
      )
      spec = get_spectrogram(
          get_whitenoise(
              sample_rate=sample_rate, duration=0.05, n_channels=2
          ),
          n_fft=n_fft,
          power=1,
      )
      self.assert_grad(transform, [spec])
  
imports: import unittest
  from typing import List
  import torch
  import torchaudio.transforms
  from parameterized import parameterized
  from torch.autograd import gradcheck, gradgradcheck
  from torchaudio_unittest.common_utils import get_spectrogram, get_whitenoise, nested_params, rnnt_utils, TestBaseMixin
label_desc: Use image node_id 16 for calling the AutogradTestMixin obj's underlying member method code with example usage: obj.test_melscale() without return types