XOM API for Processing XML with Java

[carsten.karkola AT mailbox.tu-dresden.de]

Hello,
it is maybe more an EJB question:

I'd like to subclass the Element class, to have some special methods 
for specific elements to be inserted or retrieved or to check the users 
rights, to do this.

There are two stateful beans:

 interface Schema extends EJBObject
 interface SchemaHome extends EJBHome
 class SchemaBean extends Element implements SessionBean

 interface Model extends EJBObject
 interface ModelHome extends EJBHome
 class ModelBean extends Element implements SessionBean

For one bean there is no problem to add/get specific xml attributes 
or to get the whole XML-Representation. But how to deal with
 Schema.setModel(Model model) {
   this.insertChild(model, 0); // there should be the ModelBean !?
 }
The Model/ModelBean should be a child element of SchemaBean, 
but how can I work with ModelBean in this place instead of Model 
which doesn't extend Element. Client code will use this remote call, 
so I have to use Model in the signature.

Thank you,
Carsten