diff -r 31b7e8e7132e -r e23c03dc5cf9 mercurial/changegroup.py
--- a/mercurial/changegroup.py	Fri Sep 21 18:47:04 2018 -0700
+++ b/mercurial/changegroup.py	Mon Sep 24 09:59:19 2018 -0700
@@ -19,10 +19,6 @@
     short,
 )
 
-from .thirdparty import (
-    attr,
-)
-
 from . import (
     error,
     match as matchmod,
@@ -34,10 +30,6 @@
     util,
 )
 
-from .utils import (
-    interfaceutil,
-)
-
 _CHANGEGROUPV1_DELTA_HEADER = struct.Struct("20s20s20s20s")
 _CHANGEGROUPV2_DELTA_HEADER = struct.Struct("20s20s20s20s20s")
 _CHANGEGROUPV3_DELTA_HEADER = struct.Struct(">20s20s20s20s20sH")
@@ -499,16 +491,6 @@
             return d
         return readexactly(self._fh, n)
 
-@interfaceutil.implementer(repository.irevisiondeltarequest)
-@attr.s(slots=True, frozen=True)
-class revisiondeltarequest(object):
-    node = attr.ib()
-    linknode = attr.ib()
-    p1node = attr.ib()
-    p2node = attr.ib()
-    basenode = attr.ib()
-    ellipsis = attr.ib(default=False)
-
 def _revisiondeltatochunks(delta, headerfn):
     """Serialize a revisiondelta to changegroup chunks."""