docs: public static int findMaxElementId(VoltXMLElement root) {
          int retval = 0;
          if (root != null) {
              String strId = root.attributes.get("id");
              if (strId != null) {
                  retval = Integer.parseInt(strId);
              }
              for (VoltXMLElement child : root.children) {
                  int childMaxId = findMaxElementId(child);
                  if (retval < childMaxId) {
                      retval = childMaxId;
                  }
              }
          }
          return retval;
      }