// Restores the Originator's state from a memento object.
public void Restore(Memento memento)
{
if (!(memento is DefaultMemento))
{
throw new Exception("Unknown memento class " + memento.ToString());
}
this.state = ((DefaultMemento)memento).GetState();
Console.Write("Originator: My state has changed to: " + this.state);
}