diff -r f7ff5b4fe745 -r dac438b7346e mercurial/repository.py
--- a/mercurial/repository.py	Thu Oct 11 09:26:05 2018 +0200
+++ b/mercurial/repository.py	Wed Oct 03 13:07:28 2018 -0700
@@ -312,6 +312,12 @@
     All peer instances must conform to this interface.
     """
 
+class ipeerv2(ipeerconnection, ipeercapabilities, ipeerrequests):
+    """Unified peer interface for wire protocol version 2 peers."""
+
+    apidescriptor = interfaceutil.Attribute(
+        """Data structure holding description of server API.""")
+
 @interfaceutil.implementer(ipeerbase)
 class peer(object):
     """Base class for peer repositories."""