code: public boolean insertAfterId(String id, String insString)
              throws TagTypeUnmatchException {
          return InsertByIdUtil.insertAfterId(id, insString, this);
      }
docs: <p>insert String after the element having specified id attribute</p>
  
  @param id
  @param insString
  @return true if success to insert. if no hit, return false.
  @throws TagTypeUnmatchException