code: def test_inverse_spectrogram(self):
      # create a realistic input:
      waveform = get_whitenoise(
          sample_rate=8000, duration=0.05, n_channels=2
      )
      length = waveform.shape[-1]
      spectrogram = get_spectrogram(waveform, n_fft=400)
      # test
      inv_transform = T.InverseSpectrogram(n_fft=400)
      self.assert_grad(inv_transform, [spectrogram, length])
  
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 3 for calling the AutogradTestMixin obj's underlying member method code with example usage: obj.test_inverse_spectrogram() without return types