static void Example()
{
var originator = new Example.Originator("Originator's initial state");
var caretaker = new Example.Caretaker(originator);
caretaker.Backup();
originator.DoSomething();
caretaker.Backup();
originator.DoSomething();
caretaker.Backup();
originator.DoSomething();
Console.WriteLine();
caretaker.ShowHistory();
Console.WriteLine("\nClient: Now, let's rollback!\n");
caretaker.Undo();
Console.WriteLine("\n\nClient: Once more!\n");
caretaker.Undo();
}
public Caretaker(Originator originator)
{
_originator = originator;
}