code: def test_multi_thread(self):
      text = "The quick brown fox jumps over the lazy dog."
      n = 3
      augs = [
          nac.KeyboardAug(tokenizer=text_tokenizer.split_sentence),
          nac.RandomCharAug(tokenizer=text_tokenizer.split_sentence),
      ]
  
      for num_thread in [1, 3]:
          for aug in augs:
              augmented_data = aug.augment(
                  text, n=n, num_thread=num_thread
              )
              self.assertEqual(len(augmented_data), n)
  
file_path: nlpaug/test/augmenter/char/test_char.py
imports: import unittest
  import nlpaug.augmenter.char
  import nlpaug.util.text.tokenizer
  from nlpaug.util import Action
label_desc: Use image node_id 4 for calling the TestCharacter obj's underlying member method code with example usage: obj.test_multi_thread() without return types