code: def test_values(self):
      # test wave loader
      signal, sample_rate = load_audio_file(sample_file)
      self.assertTrue(
          np.allclose(signal[:5], [-2494, -2510, -2484, -2678, -2833])
      )
      self.assertTrue(len(signal) == 123481)
      self.assertTrue(sample_rate == 44100)
      self.assertTrue(signal.shape == (123481,))
      # stereo
      signal, sample_rate = load_audio_file(stereo_sample_file)
      self.assertTrue(
          np.allclose(
              signal[:4], [[33, 38], [35, 36], [29, 34], [36, 31]]
          )
      )
      self.assertTrue(len(signal) == 182919)
      self.assertTrue(sample_rate == 44100)
      self.assertTrue(signal.shape == (182919, 2))
      # test ffmpeg loader
      signal, sample_rate = load_audio_file(stereo_sample_file)
      self.assertTrue(
          np.allclose(
              signal[:4], [[33, 38], [35, 36], [29, 34], [36, 31]]
          )
      )
      self.assertTrue(len(signal) == 182919)
      self.assertTrue(sample_rate == 44100)
      self.assertTrue(signal.shape == (182919, 2))
  
imports: from __future__ import absolute_import, division, print_function
  import io
  import unittest
  from os.path import join
  from madmom.io.audio import *
  from .None import AUDIO_PATH, DATA_PATH
label_desc: Use image node_id 3 for calling the TestLoadAudioFileFunction obj's underlying member method code with example usage: obj.test_values() without return types