def test_equals(self):
     self.assertEqual(word_search(
         'ab', ['za', 'ab', 'abc', 'zab', 'zbc']
     ), ['ab', 'abc', 'zab'])
 def test_equals_3(self):
     self.assertEqual(word_search(
         'XX', ['za', 'ab', 'abc', 'zab', 'zbc']
     ), ['None'])