@Override
    public void writeChildConstraints(final XmlWriter writer, final RadComponent child) {
      writer.startElement("splitpane");
      try {
        final String position = (String)child.getCustomLayoutConstraints();
        if (!LwSplitPane.POSITION_LEFT.equals(position) && !LwSplitPane.POSITION_RIGHT.equals(position)) {
          throw new IllegalStateException("invalid position: " + position);
        }
        writer.addAttribute("position", position);
      }
      finally {
        writer.endElement();
      }
    }
@Override
    public void writeChildConstraints(final XmlWriter writer, final RadComponent child)