--- a/mercurial/patch.py	Sat Sep 30 07:44:55 2017 -0400
+++ b/mercurial/patch.py	Sat Sep 30 07:45:07 2017 -0400
@@ -442,7 +442,6 @@
         which failed to apply and total the total number of hunks for this
         files.
         """
-        pass
 
     def exists(self, fname):
         raise NotImplementedError