package sjg.maze;import java.awt.*;/** * NullElement. * * @author Christian Hvid */public class NullElement extends Element {    private static NullElement instance = new NullElement();    public static NullElement getInstance() {        return instance;    }    private NullElement() {    }    public void draw(Graphics g, int x, int y) {    }    public boolean isSolid() {        return false;    }}