/** * Check if relation type is registered predicate. * * @param predicate the predicate as URI * @throws InvalidContentException Thrown if predicate is invalid * @throws WebserverSystemException Thrown if internal error occur * @throws RelationPredicateNotFoundException Thrown if the predicate is not registered. */ private static void checkRelationType(final URI predicate) throws RelationPredicateNotFoundException { if (!ContentRelationsUtility.validPredicate(predicate)) { throw new RelationPredicateNotFoundException( "Predicate " + predicate + " is not on the registered predicate list. "); } }