diff -r ead25aa27a43 -r 2f9ad6ca19c2 contrib/check-code.py
--- a/contrib/check-code.py	Mon May 16 21:30:53 2016 +0000
+++ b/contrib/check-code.py	Mon May 16 21:18:59 2016 +0000
@@ -328,6 +328,7 @@
     (r'^import Queue', "don't use Queue, use util.queue + util.empty"),
     (r'^import cStringIO', "don't use cStringIO.StringIO, use util.stringio"),
     (r'^import urllib', "don't use urllib, use util.urlreq/util.urlerr"),
+    (r'\.next\(\)', "don't use .next(), use next(...)"),
   ],
   # warnings
   [