--- a/mercurial/revlogutils/constants.py	Mon Sep 16 15:36:38 2024 +0200
+++ b/mercurial/revlogutils/constants.py	Mon Sep 16 15:36:44 2024 +0200
@@ -7,6 +7,7 @@
 # GNU General Public License version 2 or any later version.
 """Helper class to compute deltas stored inside revlogs"""
 
+from __future__ import annotations
 
 import struct