private void addEnds() {
   layer.addChild(n1 = PPath.createEllipse(0, 0, DIAM, DIAM));
   layer.addChild(n2 = PPath.createEllipse(0, 0, DIAM, DIAM));
   n1.setStrokePaint(veryLightGray);
   n2.setStrokePaint(veryLightGray);
   n1.setPickable(false);
   n2.setPickable(false);
   n1.offset(0, 225);
   n2.offset(0, 325);
 }
 private void addHandles() {
   layer.addChild(h1 = PPath.createRectangle(0, 0, DIAM, DIAM));
   layer.addChild(h2 = PPath.createRectangle(0, 0, DIAM, DIAM));
   h1.offset(300, 120);
   h2.offset(400, 120);
 }