@Override
public boolean createReferenceDescriptions(final EObject from,
URI exportedContainerURI, IAcceptor<IReferenceDescription> acceptor) {
if(from instanceof ResourceRef){
//add to the index pointers to ALL external subjects that have the given qualified name
Resource ref = ((ResourceRef) from).getRef();
if(ref !=null && !ref.eIsProxy()){
URI fromUri=from.eResource().getURI();
URI containerUri = getExportedSubjectUri(from);
QualifiedName name = getQualifiedNameProvider().getFullyQualifiedName(ref);
IResourceDescriptions index = resourceDescriptionsProvider.getResourceDescriptions(from.eResource().getResourceSet());
Iterable<IEObjectDescription> matches = index.getExportedObjectsByType(XturtlePackage.Literals.RESOURCE);//, name, false);