Transformer<MarkovVertex, Paint> transformer = new VertexTransformer<MarkovVertex, Paint>();
graph_panel.getRenderContext().setVertexFillPaintTransformer(
transformer);
graph_panel.getRenderContext().setEdgeLabelTransformer(
new ToStringLabeller<MarkovEdge>());
PluggableGraphMouse gm = new PluggableGraphMouse();
gm.add(new PopupMousePlugin<MarkovVertex, MarkovEdge>());
gm.add(new TranslatingGraphMousePlugin(MouseEvent.BUTTON1_MASK));
graph_panel.setGraphMouse(gm);
Transformer<MarkovVertex, String> labelTransform = new VertexLabelTransformer<MarkovVertex, String>();
graph_panel.getRenderContext()
.setVertexLabelTransformer(labelTransform);
return graph_panel;