private void StartReceiver(Action<FakeReceiver> receiverAction)
        {
            var receiver = new FakeReceiver();
            receiverAction(receiver);
            receiver.Start();

            try
            {
                var task = sender.Send();
                task.Wait();
            }
            catch (AggregateException ex)
            {
                error = ex.InnerExceptions.First();
            }
        }