private static int headingIndex(Element element) {
    String tagName = element.tagName();
    if (tagName.startsWith("h")) {
      try {
        return Integer.parseInt(tagName.substring(1));
      }
      catch (Throwable ex) {
        throw new IllegalArgumentException("Must be a header tag: " + tagName, ex);
      }
    }
    else {
      throw new IllegalArgumentException("Must be a header tag: " + tagName);
    }
  }
private static int headingIndex ( Element element ) { String tagName = element . tagName ( ) ; if ( tagName . startsWith ( "h" ) ) { try { return Integer . parseInt ( tagName . substring ( 1 ) ) ; } catch ( Throwable ex ) { throw new IllegalArgumentException ( "Must be a header tag: " + tagName , ex ) ; } } else { throw new IllegalArgumentException ( "Must be a header tag: " + tagName ) ; } }
Retrieves numeric index of a heading.
@param element
@return Index