static void Main(string[] args)
{
BookReview bookReview = new BookReview("I like the book - On the Shortness of Life by Seneca.");
bookReview.Display();
PreviousReview previous = new PreviousReview();
previous.Memento = bookReview.SaveToMemento();
System.Threading.Thread.Sleep(5000);
bookReview.Update("I think...ops...I close the file without saving...");
// notice 5 seconds delay
bookReview.Display();
bookReview.RetorePreviousReview(previous.Memento);
bookReview.Display();
}
public BookReviewMemento(BookReview bookReview)
{
Content = bookReview.Content;
LastUpdateTime = bookReview.LastUpdateTime;
}