Dev2.UndoFramework.SimpleHistory.MoveBack C# (CSharp) Method

        public void MoveBack()
        {
            if(!CanMoveBack)
            {
                throw new InvalidOperationException("History.MoveBack() cannot execute because CanMoveBack returned false (the current state is the last state in the undo buffer.");
            }
            CurrentState.PreviousAction.UnExecute();
            CurrentState = CurrentState.PreviousNode;
            Length--;
            RaiseUndoBufferChanged();
        }