public static string MimeType(this FileSystemInfoEx info)
        {
            if (info is DirectoryInfoEx)
            {
                return("Folder");
            }
            else if (info is FileInfoEx finfo)
            {
                if (info.IsSymLink())
                {
                    return("Shortcut");
                }
                var ext = finfo.Extension;
                Microsoft.Win32.RegistryKey regKey = Microsoft.Win32.Registry.ClassesRoot.OpenSubKey(ext);
                if (regKey != null && regKey.GetValue("Content Type") != null)
                {
                    return(regKey.GetValue("Content Type").ToString());
                }

                return(info.Extension);
            }
            return(string.Empty);
        }