--- a/extensions.st	Thu Jun 09 12:30:22 2016 +0200
+++ b/extensions.st	Thu Jun 09 12:31:39 2016 +0200
@@ -752,6 +752,15 @@
     "Created: 14.10.1996 / 22:27:34 / stefan"
 ! !
 
+!Object methodsFor:'converting'!
+
+asDoubleLink
+    "return a valueDoubleLink for the receiver.
+     Used to make sure the receiver can be added to a double linked list"
+
+    ^ ValueDoubleLink value:self
+! !
+
 !Object methodsFor:'dependents-interests'!
 
 expressInterestIn:aspect for:anObject sendBack:aSelector