code: def test_substitute(self):
      for aug in self.augs:
          aug.action = "substitute"
  
          self.assertLess(0, len(self.text))
          augmented_data = aug.augment(self.text)
          augmented_text = augmented_data[0]
          self.assertNotEqual(self.text, augmented_text)
  
file_path: nlpaug/test/augmenter/word/test_word_embs.py
imports: import unittest
  import os
  from dotenv import load_dotenv
  import nlpaug.augmenter.word
label_desc: Use image node_id 4 for calling the TestWordEmbsAug obj's underlying member method code with example usage: obj.test_substitute() without return types