diff -r 2af6b2d8d1d8 -r aad4b46e89bb mercurial/manifest.py
--- a/mercurial/manifest.py	Fri Aug 10 13:59:27 2018 -0700
+++ b/mercurial/manifest.py	Fri Aug 10 14:20:47 2018 -0700
@@ -1485,9 +1485,6 @@
     def rev(self, node):
         return self._revlog.rev(node)
 
-    def addgroup(self, deltas, linkmapper, transaction):
-        return self._revlog.addgroup(deltas, linkmapper, transaction)
-
 @interfaceutil.implementer(repository.imanifestrevisionwritable)
 class memmanifestctx(object):
     def __init__(self, manifestlog):