private static void OnMessageReceived(object sender,MessageReceivedEventArgs e)
{
var client = (WebSocketClient)sender;
Console.WriteLine("Received by [{0}]",((IPEndPoint)client.Socket.RemoteEndPoint).ToString());
var received_msg = Encoding.UTF8.GetString(e.DecodedMessage);
Console.WriteLine("Received message: {0}",received_msg);
var msg = new WebSocketMessage();
msg.Append(received_msg);
client.SendMessage(msg);
}