--- a/mercurial/keepalive.py	Mon Sep 16 15:36:38 2024 +0200
+++ b/mercurial/keepalive.py	Mon Sep 16 15:36:44 2024 +0200
@@ -82,6 +82,7 @@
 
 # $Id: keepalive.py,v 1.14 2006/04/04 21:00:32 mstenner Exp $
 
+from __future__ import annotations
 
 import collections
 import hashlib