code: private OWLClass getOWLClass(Object id) {
          // Special cases top and bottom
          if(NamedConcept.TOP.equals(id)) {
              return owlFactory.getOWLThing();
          } else if(NamedConcept.BOTTOM.equals(id)) {
              return owlFactory.getOWLNothing();
          } else {
              String iri = (String)id;
              return owlFactory.getOWLClass(IRI.create(iri));
          }
      }
docs: Returns the {@link OWLClass} for the corresponding internal object
  representation.
  
  @param c
  @return