public async Task receive_and_not_enqueue_stream_event_when_not_eligible()
        {
            var cts = new CancellationTokenSource(10000);
            var mockStreamStateRepo   = new Mock <IStreamStateRepo>();
            var mockResolver          = new Mock <IBusinessEventResolver>();
            var mockQueue             = new Mock <IResolutionQueue>();
            var regionId              = "r";
            var streamId              = "s";
            var newPosition           = 1;
            var eventType             = "x";
            var lastAttemptedPosition = 0;
            var firstPositionInStream = 0;
            var streamState           = new StreamState(lastAttemptedPosition, true);
            var manager     = new ResolutionManager(NullStandardLogger.Instance, mockResolver.Object, mockStreamStateRepo.Object, mockQueue.Object, null);
            var streamEvent = new StreamEvent(streamId, newPosition, null, eventType, new byte[] { });

            mockStreamStateRepo.Setup(x => x.LoadStreamStateAsync(streamId)).ReturnsAsync(streamState);
            mockResolver.Setup(x => x.CanResolve(eventType)).Returns(false);             // Make this event ineligible.

            await manager.ReceiveStreamEventAsync(regionId, streamEvent, firstPositionInStream, cts.Token);

            if (cts.IsCancellationRequested)
            {
                throw new TimeoutException();
            }

            mockQueue.VerifyNoOtherCalls();
        }