docs: public static int extractIndex(String attributeName) {
  
          int index = 0;
          // check if the value index is appended to the attribute name
          if (hasIndex(attributeName)) {
              try {
                  String temp = attributeName.substring(attributeName.lastIndexOf("[") + 1, attributeName.length() - 1);
  
                  index = Integer.parseInt(temp);
              } catch (NumberFormatException e) {
                  // ignore
              }
          }
          return index;
      }