public async Task TestWriteAsync()
        {
            using (var stream = new DuplexStream(new DummyNetworkStream(), new DummyNetworkStream())) {
                var buffer = new byte[1024];

                await stream.WriteAsync(buffer, 0, buffer.Length);

                await stream.FlushAsync();

                Assert.AreEqual(buffer.Length, stream.OutputStream.Position);
            }
        }