public void Socket_BeginConnectV4IPEndPointToV4Host_Throws()
{
Socket socket = new Socket(SocketType.Stream, ProtocolType.Tcp);
socket.DualMode = false;
Assert.Throws<SocketException>(() =>
{
socket.BeginConnect(new IPEndPoint(IPAddress.Loopback, UnusedPort), null, null);
});
}