static void Main(string[] args)
{
var subject = new Subject();
var firstSubscriber = new FirstObserver();
subject.Attach(firstSubscriber);
var secondSubscriber = new SecondObserver();
subject.Attach(secondSubscriber);
subject.BusinessLogic();
subject.BusinessLogic();
subject.Detach(secondSubscriber);
subject.BusinessLogic();
}
private static void OneThread()
{
var subject = new Subject();
var observerFirst = new FirstObserver();
subject.Attach(observerFirst);
subject.Notify();
var observerSecond = new SecondObserver();
subject.Attach(observerSecond);
subject.Attach(observerSecond);
subject.Notify();
subject.Detach(observerSecond);
subject.Notify();
}