public static ITextHandOff CreateMultiObserver(this IEnumerable<ITextHandOff> channels)
 {
     var multiobserver = new TextHandoffBroadcast();
     foreach(var channel in channels)
         multiobserver.AddSubscriber(channel);
     return multiobserver;
 }
        public void When_notifying_one_observer()
        {
            var observerA = new TextHandOffObserver();

            var multiObserver = new TextHandoffBroadcast();
            multiObserver.AddSubscriber(observerA);

            multiObserver.Handoff("TEST!");

            Assert.That(observerA.ReceivedText, Is.EqualTo("TEST!"));
        }