--- a/tests/test-wireproto.py	Mon Dec 16 02:41:24 2024 -0500
+++ b/tests/test-wireproto.py	Mon Dec 16 03:04:44 2024 -0500
@@ -1,5 +1,9 @@
 import sys
 
+from typing import (
+    Set,
+)
+
 from mercurial import (
     error,
     pycompat,
@@ -55,8 +59,8 @@
     def close(self):
         pass
 
-    def capabilities(self):
-        return [b'batch']
+    def capabilities(self) -> Set[bytes]:
+        return {b'batch'}
 
     def _call(self, cmd, **args):
         args = pycompat.byteskwargs(args)