/** Sets the new referent. */
 public void setRef(Attribute referent) {
   AttributeImpl oldRef = (AttributeImpl) getReferent();
   if (oldRef == referent) return;
   oldRef.removeListener(this);
   super.setSharedComponent(referent);
   firePropertyChangeEvent(PROP_ATTRIBUTE_REF, oldRef, referent);
   forceFireEvent();
 }
 /** Creates a new instance of AttributeRef */
 public AttributeRef(AXIModel model, SchemaComponent component, Attribute referent) {
   super(model, component);
   super.setSharedComponent(referent);
 }