code: def test_2(self):
      dictionary = Dictionary.Instance()
      word = dictionary.lookup(Text("không có từ này"))
      self.assertEqual(None, word)
  
imports: from unittest import TestCase
  from underthesea.dictionary import Dictionary
  from underthesea.feature_engineering.text import Text
label_desc: Use image node_id 2 for calling the TestDictionary obj's underlying member method code with example usage: obj.test_2() without return types