code: def test_fft_window(self):
      # use a signal
      from madmom.audio.signal import Signal
  
      signal = Signal(sample_file)
      # scale the signal to float and range -1..1
      scaling = float(np.iinfo(signal.dtype).max)
      scaled_signal = signal / scaling
      # calculate the STFTs of both signals
      result = ShortTimeFourierTransform(signal)
      scaled_result = ShortTimeFourierTransform(scaled_signal)
      # both STFTs must be the same
      self.assertTrue(np.allclose(result, scaled_result))
      # if now window is given, a uniformly distributed one should be used
      result = ShortTimeFourierTransform(signal, window=None)
      self.assertTrue(
          np.allclose(
              result.fft_window, np.ones(2048, dtype=float) / scaling
          )
      )
      scaled_result = ShortTimeFourierTransform(
          scaled_signal, window=None
      )
      self.assertTrue(scaled_result.fft_window is None)
  
imports: from __future__ import absolute_import, division, print_function
  import sys
  import unittest
  from os.path import join
  from madmom.audio.spectrogram import Spectrogram
  from madmom.audio.stft import *
  from .None import AUDIO_PATH
label_desc: Use image node_id 4 for calling the ShortTimeFourierTransformClass obj's underlying member method code with example usage: obj.test_fft_window() without return types