code: private void commentLinesAfter( String content, int line ) {
          int offset = rootElement.getElement(line).getEndOffset();
          // End of comment not found, nothing to do
          int endDelimiter = indexOf(content, getEndDelimiter(), offset);
          if (endDelimiter < 0)
              return;
          // Matching start/end of comment found, comment the lines
          int startDelimiter = lastIndexOf(content, getStartDelimiter(), endDelimiter);
          if (startDelimiter < 0 || startDelimiter <= offset) {
              doc.setCharacterAttributes(offset, endDelimiter - offset + 1, comment, false);
          }
      }
docs: /*
  Highlight comment lines to matching end delimiter