--- a/mercurial/testing/revlog.py	Mon Sep 16 15:36:38 2024 +0200
+++ b/mercurial/testing/revlog.py	Mon Sep 16 15:36:44 2024 +0200
@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 import unittest
 
 # picked from test-parse-index2, copied rather than imported