static public void SetMarkerStyle(this ScintillaGateway document, int marker, Bitmap bitmap)
        {
            int mask = document.GetMarginMaskN(1);

            string bookmark_xpm = ConvertToXPM(bitmap, "#FF00FF");

            document.MarkerDefinePixmap(marker, bookmark_xpm);
            document.SetMarginMaskN(1, (1 << marker) | mask);
        }