@Override
 public void addNode(GraphNode node) {
   super.addNode(node);
   if (node instanceof SVGGraphNode) {
     final SVGGraphNode svgGraphNode = (SVGGraphNode) node;
     graphController.updateSVGDocument(
         new Runnable() {
           @Override
           public void run() {
             float opacity = svgGraphNode.getOpacity();
             svgGraphNode.setOpacity(0);
             mainGroup.appendChild(svgGraphNode.getSVGElement());
             svgGraphNode.setOpacity(opacity);
           }
         });
   }
 }