public string CombineURL(string url = "")
        {
            IntPtr buffer = PInvokeUtils.NativeUtf16FromString(url, 2048);
            var    res    = _api.SciterCombineURL(_he, buffer, 2048);
            string s      = PInvokeUtils.StringFromNativeUtf16(buffer);

            PInvokeUtils.NativeUtf16FromString_FreeBuffer(buffer);
            return(s);
        }