public void TestDoubleAdd()
{
Msg1Sub sub = new Msg1Sub();
bus.RegisterSubscriber(sub);
Assert.ThrowsException <System.ArgumentException>(() => bus.RegisterSubscriber(sub));
}
public void UnregisterHandler()
{
var sub = new Msg1Sub();
bus.RegisterSubscriber(sub);
Assert.AreEqual(1, bus.SubscriberCount);
bus.UnregisterSubscriber(sub);
Assert.AreEqual(0, bus.SubscriberCount);
bus.Send(new MyMessage1());
AssertHandleCounts();
}