// So far we have just been using PNode, but of course PNode has many
        // subclasses that you can try out to.
        public void CreateNodeUsingExistingClasses()
        {
            PLayer layer = Canvas.Layer;

            layer.AddChild(PPath.CreateEllipse(0, 0, 100, 100));
            layer.AddChild(PPath.CreateRectangle(0, 100, 100, 100));
            layer.AddChild(new PText("Hello World"));

            // Here we create an image node that displays a thumbnail
            // image of the root node. Note that you can easily get a thumbnail
            // of any node by using PNode.ToImage().
            PImage image = new PImage(layer.ToImage(300, 300, Color.Transparent));

            layer.AddChild(image);
        }