code: public static org.w3c.dom.Document getW3cDocument(JsonElement value, String rootName) {
          Element root = getElement(value, rootName);
          try {
              DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
              factory.setNamespaceAware(true);
              DocumentBuilder builder = factory.newDocumentBuilder();
              DOMImplementation impl = builder.getDOMImplementation();
  
              return DOMConverter.convert(new Document(root), impl);
          } catch (ParserConfigurationException e) {
              throw new IllegalStateException(e);
          }
      }
docs: Convert any JsonElement into an w3c DOM tree.
  
  @param value
  a json element
  @param rootName
  the root name of the xml
  @return a Document