return null;
}
NodeIterator it = s_i.listPropertyValues(p_p);
while (it.hasNext()) {
RDFNode node = it.nextNode();
if (node.isLiteral()
&& OntologyElement.LITERAL.equals(qr.getType())) {
qr.add(wrap((Literal) node));
} else if (node.canAs(Individual.class)
&& OntologyElement.INDIVIDUAL.equals(qr.getType())) {