public void ClusterDomainEventPublisher_must_publish_seen_changed()
{
var subscriber = CreateTestProbe();
_publisher.Tell(new InternalClusterAction.Subscribe(subscriber.Ref, ClusterEvent.SubscriptionInitialStateMode.InitialStateAsSnapshot, ImmutableHashSet.Create(typeof(ClusterEvent.SeenChanged))));
subscriber.ExpectMsg<ClusterEvent.CurrentClusterState>();
_publisher.Tell(new InternalClusterAction.PublishChanges(g2));
subscriber.ExpectMsg<ClusterEvent.SeenChanged>();
subscriber.ExpectNoMsg(TimeSpan.FromMilliseconds(500));
_publisher.Tell(new InternalClusterAction.PublishChanges(g3));
subscriber.ExpectMsg<ClusterEvent.SeenChanged>();
subscriber.ExpectNoMsg(TimeSpan.FromMilliseconds(500));
}