@Override
 protected void writeAdditional(
     DrawComponent dc, HierarchicalStreamWriter writer, MarshallingContext context) {
   LineDrawComponent ldc = (LineDrawComponent) dc;
   writer.addAttribute(CONNECT, "" + ldc.isConnect());
 }
 @Override
 protected void readAdditional(
     DrawComponent dc, HierarchicalStreamReader reader, UnmarshallingContext context) {
   LineDrawComponent ldc = (LineDrawComponent) dc;
   ldc.setConnect(Boolean.parseBoolean(reader.getAttribute(CONNECT)));
 }