diff -r 96d130697f07 -r b95a5bb58653 mercurial/unionrepo.py
--- a/mercurial/unionrepo.py	Mon Jan 26 15:18:07 2015 -0800
+++ b/mercurial/unionrepo.py	Thu Jan 22 11:09:34 2015 -0500
@@ -160,9 +160,6 @@
     def baserevdiff(self, rev1, rev2):
         return filelog.filelog.revdiff(self, rev1, rev2)
 
-    def _file(self, f):
-        self._repo.file(f)
-
 class unionpeer(localrepo.localpeer):
     def canpush(self):
         return False