code: private static Document emptyDocument() {
          try {
              return DocumentBuilderFactory.newInstance()
                  .newDocumentBuilder()
                  .newDocument();
          } catch (final ParserConfigurationException ex) {
              throw new IllegalStateException(
                  // @checkstyle LineLength (1 line)
                  "Could not instantiate DocumentBuilderFactory and build empty Document",
                  ex
              );
          }
      }
docs: Create empty DOM Document.
  @return Document