code: def load_mel_spectrogram(file_path, n_mels=128, fmax=8000):
      try:
          import librosa
      except ModuleNotFoundError:
          raise ModuleNotFoundError(
              "Missed librosa library. Install import librosa by `pip install librosa`"
          )
  
      audio, sampling_rate = AudioLoader.load_audio(file_path)
      return librosa.feature.melspectrogram(
          y=audio, sr=sampling_rate, n_mels=n_mels, fmax=fmax
      )
  
label_desc: Use image node_id 2 for calling the AudioLoader obj's underlying member method code with example usage: obj.load_mel_spectrogram(file_path, n_mels, fmax) and returns: librosa