Issue #24254: Preserve class attribute definition order.
diff --git a/Lib/test/test_sys.py b/Lib/test/test_sys.py
index 4435d69..3131f36 100644
--- a/Lib/test/test_sys.py
+++ b/Lib/test/test_sys.py
@@ -1084,7 +1084,7 @@
         check((1,2,3), vsize('') + 3*self.P)
         # type
         # static type: PyTypeObject
-        fmt = 'P2n15Pl4Pn9Pn11PIP'
+        fmt = 'P2n15Pl4Pn9Pn11PIPP'
         if hasattr(sys, 'getcounts'):
             fmt += '3n2P'
         s = vsize(fmt)