code: def test_standard(self):
      aug = naa.NormalizeAug(method="standard")
      augmented_data = aug.augment(self.audio)
      augmented_audio = augmented_data[0]
  
      self.assertFalse(np.array_equal(self.audio, augmented_audio))
      self.assertEqual(len(self.audio), len(augmented_audio))
  
file_path: nlpaug/test/augmenter/audio/test_normalization.py
imports: import unittest
  import os
  import numpy
  from dotenv import load_dotenv
  import nlpaug.augmenter.audio
  from nlpaug.util import AudioLoader
label_desc: Use image node_id 6 for calling the TestNormalization obj's underlying member method code with example usage: obj.test_standard() without return types