code: def test_methods(self):
      result = Phase(sample_file)
      self.assertIsInstance(result.local_group_delay(), LocalGroupDelay)
      self.assertIsInstance(result.lgd(), LocalGroupDelay)
  
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 3 for calling the PhaseClass obj's underlying member method code with example usage: obj.test_methods() without return types