code: def freq_power(title, audio, sample_rate, aug_audio=None):
      audio_fft = np.fft.rfft(audio)
      audio_fft /= len(audio_fft)
  
      freq_bins = np.arange(0, len(audio_fft), 1.0) * (
          sample_rate * 1.0 / len(audio_fft)
      )
      plt.plot(
          freq_bins / 1000,
          10 * np.log10(audio_fft),
          color="#FF0000",
          linewidth=0.02,
      )
  
      if aug_audio is not None:
          aug_audio_fft = np.fft.rfft(aug_audio)
          aug_audio_fft /= len(aug_audio_fft)
  
          aug_freq_bins = np.arange(0, len(aug_audio_fft), 1.0) * (
              sample_rate * 1.0 / len(aug_audio_fft)
          )
          plt.plot(
              aug_freq_bins / 1000,
              10 * np.log10(aug_audio_fft),
              color="#000000",
              linewidth=0.02,
          )
  
      plt.title(title)
      plt.xlabel("Frequency (k Hz)")
      plt.ylabel("Power (dB)")
      plt.tight_layout()
      plt.show()
  
imports: import numpy
label_desc: Use image node_id 2 for calling the AudioVisualizer obj's underlying member method code with example usage: obj.freq_power(title, audio, sample_rate, aug_audio) without return types