builder.setStroke(Color.RED);
builder.setLocation(150, 50);
builder.endGroup();
builder.setLocation(50, 100);
final Shape s = builder.getProduct();
System.out.println(s.accept(new Size()) + " basic shapes");
// calculate the bounding box
final Location b = s.accept(new BoundingBox());
final Rectangle r = (Rectangle) b.getChild();