code: def test_mode(self):
      for mode in ["left", "right", "neighbor", "random"]:
          aug = nas.RandomSentAug(mode="left")
          aug_data = aug.augment(self.data)
          self.assertNotEqual(self.data, aug_data[0])
          self.assertEqual(4, len(aug.model.tokenize(aug_data[0])))
  
imports: import unittest
  import os
  import nlpaug.augmenter.sentence
label_desc: Use image node_id 2 for calling the TestRandomSentenceAug obj's underlying member method code with example usage: obj.test_mode() without return types