p.getNanoGraph().setLayout(new CircularLayoutAlgorithm(200));
DefaultNodeRenderer r = new DefaultNodeRenderer();
// r.setBodyColor(new GradientPaint(0,0,Color.YELLOW, 600, 600, Color.RED));
p.getNanoGraph().registerNodeRenderer(String.class, r);
p.getNanoGraph().setBackground(new GridBackGround());
this.getContentPane().add(p);
}