if (startVertex != null)
{
final VisualizationViewer<GUINode, GUILink> vv = (VisualizationViewer<GUINode, GUILink>) e.getSource();
vv.removePostRenderPaintable(edgePaintable);
vv.removePostRenderPaintable(arrowPaintable);
<BUG>final GUINode guiNode = (GUINode) canvas.getVertex(e);
final Node node = guiNode == null? null : guiNode.getAssociatedNode();</BUG>
if (node != null && startVertex.getAssociatedNode() != node)
{
if (guiNode.getLayer() == startVertex.getLayer ())

if (startVertex != null)
{
final VisualizationViewer<GUINode, GUILink> vv = (VisualizationViewer<GUINode, GUILink>) e.getSource();
vv.removePostRenderPaintable(edgePaintable);
vv.removePostRenderPaintable(arrowPaintable);
final GUINode guiNode = canvas.getVertex(e);
final Node node = guiNode == null? null : guiNode.getAssociatedNode();
if (node != null && startVertex.getAssociatedNode() != node)
{
if (guiNode.getLayer() == startVertex.getLayer ())
