graph.setMarqueeHandler(new MyMarqueeHandler());
// Construct Command History
//
// Create a GraphUndoManager which also Updates the ToolBar
undoManager = new GraphUndoManager() {
// Override Superclass
public void undoableEditHappened(UndoableEditEvent e) {
// First Invoke Superclass
super.undoableEditHappened(e);
// Then Update Undo/Redo Buttons