public IOntology[] getImportedOntologies() {
if(imported == null){
checkModel();
imported = new ArrayList<IOntology>();
OWLOntology defaultont = (OWLOntology) resource;
Collection list = defaultont.getImportResources();
for(Object o: list){
if(o instanceof RDFResource){
//TODO: maybe there is some tripplestore trick that I can use
// and avoid loading imported ontology again
RDFResource on = (RDFResource) o;