}
public void updateBounds(){
dependencyGraph.updatePertLevels();
GraphicConfiguration config=GraphicConfiguration.getInstance();
Point2D origin=new Point2D.Double(config.getPertXOffset(),config.getPertYOffset());
Rectangle2D ref=new Rectangle2D.Double(config.getPertXOffset(),config.getPertYOffset(),config.getPertCellWidth(),config.getPertCellHeight());
int row=0;
int col=-1;
setEmpty();
for (Iterator i=cache.getIterator();i.hasNext();){
GraphicNode current=(GraphicNode)i.next();