Catrobat.IDE.Core.Formulas.Editor.FormulaEditor.Undo C# (CSharp) Метод

        public bool Undo()
        {
            if (_undoStack.Count == 0) return false;
            PushState(_redoStack);
            PopState(_undoStack);
            RaisePropertyChanged(() => CanUndo);
            RaisePropertyChanged(() => CanRedo);
            return true;
        }