public void send_partial_message()
{
var buf = new SocketBufferFake();
var expected = "Hello world!";
var sut = new StringEncoder();
sut.Prepare(expected);
sut.Send(buf);
sut.OnSendCompleted(5);
sut.Send(buf);
BitConverter.ToInt32(buf.Buffer, 0).Should().Be(expected.Length);
var actual = Encoding.UTF8.GetString(buf.Buffer, buf.Offset, buf.Count);
actual.Should().Be("ello world!");
}