code: def test_special_char(self):
      text = "#"
      aug = nac.KeyboardAug(min_char=1)
      augmented_data = aug.augment(text)
      augmented_text = augmented_data[0]
      self.assertNotEqual(text, augmented_text)
  
      # No mapping, return original value
      text = "~"
      augs = [nac.KeyboardAug(min_char=1), nac.OcrAug(min_char=1)]
      for aug in augs:
          augmented_data = aug.augment(text)
          augmented_text = augmented_data[0]
          self.assertEqual(text, augmented_text)
  
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 9 for calling the TestCharacter obj's underlying member method code with example usage: obj.test_special_char() without return types