FilterNode.Children no expansion icon on leaf nodes

Hello,

I'm creating a logical view for a projet and filtering files in some directories. Following this tutorial it is quite easy to do so:
http://wiki.netbeans.org/DevFaqNodesDecorating

But then all files have the expansion handle ("+") in the tree. It's only when you click on it that it disappears.

Is there a way to force it to LEAF or otherwise to have an eager evaluation of the children?

In the tutorial above, this problem is also present but the link to the solution is broken:
"Note that if you're showing the filtered nodes in a tree view according to the code above, you might find expansion handles on leaf nodes. This thread from the dev@openide list discusses some solutions to this problem."
=> http://openide.netbeans.org/servlets/ReadMsg?listName=dev&msgNo=11595

Thanks




Attachments: 
http://forums.netbeans.org//files/netbeans_filternode_110.png