--- a/TreeSet.st	Mon Jun 24 21:44:20 2013 +0200
+++ b/TreeSet.st	Tue Jun 25 13:22:55 2013 +0200
@@ -117,8 +117,17 @@
 	^ sortKey
 ! !
 
+!TreeSet methodsFor:'testing'!
+
+isFixedSize
+    "return true if the receiver cannot grow"
+
+    ^ false
+! !
+
 !TreeSet class methodsFor:'documentation'!
 
 version_CVS
-    ^ '$Header: /cvs/stx/stx/libbasic2/TreeSet.st,v 1.2 2012-08-05 09:31:37 cg Exp $'
+    ^ '$Header: /cvs/stx/stx/libbasic2/TreeSet.st,v 1.3 2013-06-25 11:22:55 cg Exp $'
 ! !
+