[JXTA discuss] peergroups and services

Hello.

Is it possible to force members of a group to instantiate specific services,
to work in that group?

e.g.

MyGroup requires MyDiscoveryService

If a peer joins MyGroup and then instantiate AnotherDiscoveryService for
MyGroup, it should not be able to publish/discovery advertisements in
MyGroup. 

How this can be done? 
Is there a local check, or a distributed one (i.e. other peers refuse
messages which are generated by the wrong service)?

Thanks

Michele Amoretti