Update test_tokenize.py

Author: wannaphong

tests/core/test_tokenize.py

@@ -355,6 +355,11 @@ def test_word_tokenize(self):
             "ไฟ", word_tokenize("รถไฟฟ้า", custom_dict=dict_trie(["ไฟ"]))
         )
 
+        with self.assertRaises(NotImplementedError):
+            word_tokenize(
+                "รถไฟฟ้า", custom_dict=dict_trie(["ไฟ"]), engine="icu"
+            )
+
     def test_etcc(self):
         self.assertEqual(etcc.segment(None), [])
         self.assertEqual(etcc.segment(""), [])