Fix running test_tokenize directly
diff --git a/Lib/test/test_tokenize.py b/Lib/test/test_tokenize.py
index 90438e7..77c0423 100644
--- a/Lib/test/test_tokenize.py
+++ b/Lib/test/test_tokenize.py
@@ -3,7 +3,7 @@
                      STRING, ENDMARKER, ENCODING, tok_name, detect_encoding,
                      open as tokenize_open, Untokenizer)
 from io import BytesIO
-from unittest import TestCase, mock
+from unittest import TestCase, mock, main
 import os
 import token
 
@@ -1564,4 +1564,4 @@
 
 
 if __name__ == "__main__":
-    unittest.main()
+    main()