private void Replace(Undefined control, GrammarEventArgs eventArgs)
        {
            GrammarNodeD itemToReplace = control.Reference.getReference();

            GrammarNodeD newItem = model.Functions.Replace(itemToReplace, eventArgs.SymbolType, eventArgs.NewName);

            view.Functions.Replace(itemToReplace, newItem);

            ReDraw();
        }
 internal void Listen(Undefined undefined)
 {
     undefined.ControlEvent += new Undefined.ControlEventHandler(undefined_ControlEvent);
 }