docs: public static Element nextElement(XMLExtendedStreamReader reader, Namespace expectedNamespace) throws XMLStreamException {
          Element element = nextElement(reader);
  
          if (element == null) {
              return null;
          } else if (element != Element.UNKNOWN
                  && expectedNamespace.equals(Namespace.forUri(reader.getNamespaceURI()))) {
              return element;
          }
  
          throw unexpectedElement(reader);
      }