private void demoBorder() {
    target.setLayout(new RowLayout());

    LayoutPanel inner = new LayoutPanel(false); // row
    inner.add(new Thing("West"), 0.2f);
    inner.add(new Thing("Center"));
    inner.add(new Thing("East"), 0.2f);

    target.add(new Thing("North"), 0.2f);
    target.add(inner, LayoutConstraints.HIDDEN);
    target.add(new Thing("South"), 0.2f);
  }
 private void demoSidebarAndMargin() {
   target.setLayout(new RowLayout(false));
   target.add(new Thing("Sidebar"), 0.2f);
   target.add(new Thing("Body"));
   target.add(new Thing("Margin"), 50);
 }
 private void demoButtonsAndBody() {
   target.setLayout(new RowLayout());
   target.add(new Thing("Buttons"), 50);
   target.add(new Thing("Body"));
 }