New class syntax.
diff --git a/Lib/lib-stdwin/Abstract.py b/Lib/lib-stdwin/Abstract.py
index 45d68ae..c6fe137 100644
--- a/Lib/lib-stdwin/Abstract.py
+++ b/Lib/lib-stdwin/Abstract.py
@@ -10,7 +10,7 @@
# For historical reasons, button creation methods are called
# define() while split creation methods are called create().
-class AbstractParent():
+class AbstractParent:
#
# Upcalls from child to parent
#
@@ -33,7 +33,7 @@
def scroll(self, (area, (dh, dv))): unimpl()
def settimer(self, itimer): unimpl()
-class AbstractChild():
+class AbstractChild:
#
# Downcalls from parent to child
#
@@ -59,5 +59,5 @@
# Certain upcalls and downcalls can be handled transparently, but
# for others (e.g., all geometry related calls) this is not possible.
-class AbstractSplit() = AbstractChild(), AbstractParent():
+class AbstractSplit(AbstractChild, AbstractParent):
pass