public void Receive_Fires_ReceivedMessage()
        {
            var tcs = new TaskCompletionSource <ReceivedMessageEventArgs>();

            _sut.ReceivedMessage += (s, e) => {
                tcs.SetResult(e);
            };

            SendTestMessage();

            _sut.Receive();

            tcs.Task.Wait();

            Assert.IsNotNull(tcs.Task.Result.Message);
        }