public ObserversViaSpecialInterfaces()
{
var person = new Person2();
//IDisposable sub = person.Subscribe(this);
// Reactive Extensions event.
person.OfType <FallsIllEvent>().Subscribe(args =>
Console.WriteLine($"A doctor is required at {args.Address}"));
person.FallsIll();
}
public Subscription(Person2 person, IObserver <Event> observer)
{
_person = person;
Observer = observer;
}