public void removePage(BPageModel model) {
   if (model != null) {
     pageModels.remove(model.getName());
     for (BShape shape : model.getShapes()) removeShape(shape.getModel());
     model = null;
   }
 }
 public void addPage(BPageModel model) {
   if (model.getName() == null) model.setName(pageCounter.getPageName());
   pageModels.put(model.getName(), model);
   model.setData(this);
 }