public <A> Optional<A> get(QName key, Class<A> clss) {
String attrName = key.getLocalPart();
Object value = doGetProperties().get(attrName);
public <A> Optional<A> get(QName key, Class<A> clss) {
String attrName = key.getLocalPart();
Object value = doGetProperties().get(attrName);