diff -r d909c44d29e1 -r a269fa55467e mercurial/filelog.py
--- a/mercurial/filelog.py	Mon Sep 24 12:49:17 2018 -0700
+++ b/mercurial/filelog.py	Mon Sep 24 13:35:50 2018 -0700
@@ -67,9 +67,6 @@
     def children(self, node):
         return self._revlog.children(node)
 
-    def deltaparent(self, rev):
-        return self._revlog.deltaparent(rev)
-
     def iscensored(self, rev):
         return self._revlog.iscensored(rev)