code: def test_n_output_spectrogram(self):
      mel_spectrogram = AudioLoader.load_mel_spectrogram(
          self.sample_wav_file, n_mels=128
      )
      #
      flows = [
          naf.Sequential(
              [nas.FrequencyMaskingAug(), nas.TimeMaskingAug()]
          ),
          naf.Sometimes(
              [nas.FrequencyMaskingAug(), nas.TimeMaskingAug()],
              aug_p=0.9,
          ),
          naf.Sequential(
              [
                  naf.Sequential(
                      [nas.FrequencyMaskingAug(), nas.TimeMaskingAug()]
                  ),
                  naf.Sometimes(
                      [nas.FrequencyMaskingAug(), nas.TimeMaskingAug()],
                      aug_p=0.9,
                  ),
              ]
          ),
      ]
  
      for flow in flows:
          augmented_mel_spectrograms = flow.augment(
              mel_spectrogram, n=3
          )
          self.assertGreater(len(augmented_mel_spectrograms), 1)
          for augmented_mel_spectrogram in augmented_mel_spectrograms:
              self.assertFalse(
                  np.array_equal(
                      mel_spectrogram, augmented_mel_spectrogram
                  )
              )
  
      self.assertLess(0, len(flows))
  
imports: import unittest
  import os
  import numpy
  from dotenv import load_dotenv
  import nlpaug.augmenter.char
  import nlpaug.augmenter.word
  import nlpaug.augmenter.audio
  import nlpaug.augmenter.spectrogram
  import nlpaug.flow
  from nlpaug.util.audio.loader import AudioLoader
  from nlpaug.util import Action
label_desc: Use image node_id 6 for calling the TestFlow obj's underlying member method code with example usage: obj.test_n_output_spectrogram() without return types