code: def test_case_sentsitive(self):
      texts = [
          "Fwd: Mail for solution",
      ]
  
      reserved_tokens = [
          ["FWD", "Forward"],
      ]
      aug = naw.ReservedAug(
          reserved_tokens=reserved_tokens, case_sensitive=True
      )
  
      for text in texts:
          augmented_data = aug.augment(text)
          augmented_text = augmented_data[0]
          self.assertEqual(augmented_text, text)
  
      aug = naw.ReservedAug(
          reserved_tokens=reserved_tokens, case_sensitive=False
      )
  
      for text in texts:
          augmented_data = aug.augment(text)
          augmented_text = augmented_data[0]
          self.assertNotEqual(augmented_text, text)
  
      text = "Dear NLP, text, texttt Thanks. Regards NLPAug"
      reserved_tokens = [
          ["1", "Regards"],
      ]
  
      aug = naw.ReservedAug(
          reserved_tokens=reserved_tokens, case_sensitive=False
      )
      for _ in range(10):
          augmented_data = aug.augment(text)
          augmented_text = augmented_data[0]
          self.assertNotEqual(augmented_text, text)
  
      text = "Dear NLP, text, texttt Thanks. regards NLPAug"
      reserved_tokens = [["Best Regards", "Regards"]]
      aug = naw.ReservedAug(
          reserved_tokens=reserved_tokens, case_sensitive=False
      )
      for _ in range(10):
          augmented_data = aug.augment(text)
          augmented_text = augmented_data[0]
          self.assertNotEqual(augmented_text, text)
          self.assertTrue("Best Regards" in augmented_text)
  
      text = "Dear NLP, text, texttt Thanks. best regards NLPAug"
      reserved_tokens = [["Best Regards", "Regards"]]
      aug = naw.ReservedAug(
          reserved_tokens=reserved_tokens, case_sensitive=False
      )
      for _ in range(10):
          augmented_data = aug.augment(text)
          augmented_text = augmented_data[0]
          self.assertNotEqual(augmented_text, text)
          self.assertTrue("Regards" in augmented_text)
  
file_path: nlpaug/test/augmenter/word/test_reserved.py
imports: import unittest
  import nlpaug.augmenter.word
label_desc: Use image node_id 6 for calling the TestReserved obj's underlying member method code with example usage: obj.test_case_sentsitive() without return types