framework/application/data/src/main/java/org/ldp4j/application/data/PropertyHelperImpl.java
@Override
	public <T extends Serializable, S extends Individual<T,S>> T firstIndividual(final Class<? extends S> clazz) {
		Property property=getProperty();
		if(property==null) {
			return null;
		}
		IndividualExtractor<T,S> extractor=IndividualExtractor.newInstance(clazz);
		for(Value value:property) {
			value.accept(extractor);
			if(extractor.isAvailable()) {
				return extractor.getValue().id();
			}
		}
		return null;
	}
@Override
	public <T extends Serializable, S extends Individual<T,S>> T firstIndividual(final Class<? extends S> clazz) {
		Property property=getProperty();
		if(property==null) {
			return null;
		}
		IndividualExtractor<T,S> extractor=IndividualExtractor.newInstance(clazz);
		for(Value value:property) {
			value.accept(extractor);
			if(extractor.isAvailable()) {
				return extractor.getValue().id();
			}
		}
		return null;
	}
{@inheritDoc}