Set<OWLClass> result=new HashSet<OWLClass>();
OWLDataFactory factory=getDataFactory();
for (AtomicConcept concept : hierarchyNode.getEquivalentElements())
if (!Prefixes.isInternalIRI(concept.getIRI()))
result.add(factory.getOWLClass(IRI.create(concept.getIRI())));
return new OWLClassNode(result);
}