diff -r 55d132525155 -r 642e31cb55f0 mercurial/unionrepo.py
--- a/mercurial/unionrepo.py	Mon Feb 21 13:03:43 2022 -0700
+++ b/mercurial/unionrepo.py	Mon Feb 21 13:08:28 2022 -0700
@@ -209,7 +209,7 @@
         return False
 
 
-class unionrepository(object):
+class unionrepository:
     """Represents the union of data in 2 repositories.
 
     Instances are not usable if constructed directly. Use ``instance()``