public List<OWLOntologyChange> addMatrixValue(OWLObject rowObj, Object columnObj, Object value) {
   if (columnObj instanceof OWLObjectProperty) {
     Set<OWLNamedIndividual> values = null;
     if (value instanceof OWLNamedIndividual) {
       values = Collections.singleton((OWLNamedIndividual) value);
     } else if (value instanceof Set) {
       // @@TODO check the contents of the set
       values = (Set<OWLNamedIndividual>) value;
     }
     if (values != null) {
       return helper.addRelationships(
           (OWLNamedIndividual) rowObj,
           (OWLObjectProperty) columnObj,
           values,
           mngr.getActiveOntology());
     }
   } else if (columnObj instanceof OWLDataProperty) {
     Set<OWLLiteral> values = null;
     if (value instanceof OWLLiteral) {
       values = Collections.singleton((OWLLiteral) value);
     } else if (value instanceof Set) {
       // @@TODO check the contents of the set
       values = (Set<OWLLiteral>) value;
     }
     if (values != null) {
       return helper.addRelationships(
           (OWLNamedIndividual) rowObj,
           (OWLDataProperty) columnObj,
           values,
           mngr.getActiveOntology());
     }
   }
   return super.addMatrixValue(rowObj, columnObj, value);
 }
 public Object getMatrixValue(OWLObject entity, Object prop) {
   if (entity instanceof OWLIndividual) {
     if (prop instanceof OWLObjectProperty) {
       return helper.getRelationships((OWLIndividual) entity, (OWLObjectProperty) prop);
     } else if (prop instanceof OWLDataProperty) {
       return helper.getRelationships((OWLIndividual) entity, (OWLDataProperty) prop);
     } else {
       return super.getMatrixValue(entity, prop);
     }
   }
   return null;
 }
 public List<OWLOntologyChange> setMatrixValue(OWLObject ind, Object prop, Object value) {
   if (prop instanceof OWLObjectProperty) {
     return helper.setRelationships(
         (OWLNamedIndividual) ind,
         (OWLObjectProperty) prop,
         (Set<OWLNamedIndividual>) value,
         mngr.getActiveOntology());
   } else if (prop instanceof OWLDataProperty) {
     return helper.setRelationships(
         (OWLNamedIndividual) ind,
         (OWLDataProperty) prop,
         (Set<OWLLiteral>) value,
         mngr.getActiveOntology());
   } else {
     return super.setMatrixValue(ind, prop, value);
   }
 }