* Create a new controller with default node and edge controllers.
* Set the node renderer to a bubble renderer, and the edge renderer
* to an arc renderer.
*/
public BubbleGraphController() {
NodeController nc = new BasicNodeController(this);
nc.setNodeRenderer(new BubbleRenderer());
setNodeController(nc);
EdgeController ec = new BasicEdgeController(this);
ec.setEdgeRenderer(new ArcRenderer());
setEdgeController(ec);