other solution: i defined an other set with the interface, but then i get
a org.hibernate.MappingException: Could not determine type for: java.util.Set, for columns exception
but i don't want the hibernate to map it, i just used this field pojolike..
I think you can make your interface extends java.io.Serializable
I extended the interface, but then i got some ontomany relation exception.
But i found the magic @Transient annotation, so my 2. solution works i think.