@Override
public void gvExternalGraph(Graphviz graph) {
graph.connectGraph(this, subContext, Graphviz.ALPHABET);
}
@Override
public void gvInternalGraph(Graphviz graph) {
graph.edge(gvNodeID(), gvNodeID(), "label", Graphviz.ALPHABET);
graph.connectGraph(this, next, Graphviz.ALPHABET);
}