public async Task EventStream_Add__Single_Event() { string streamName = "Aggregate-1"; var target = new EventStream(streamName, streamStore, logger); await target.Add(Streams.Aggregate_1.First()); await streamStore.Received().AddEventsToStream(streamName, Arg.Is <IEnumerable <Event> >(a => a.First() == Streams.Aggregate_1.First())); }