public static void Main(string[] args)
        {
            // two things it can do: get new access token, or refresh existing one
            // if a data.ini file exists, use that and refresh
            // if not exists, create new
            var dataIniFileName = args.FirstOrDefault() ?? DefaultDataIniFileName;
            var data            = OAuthData.TryReadData(dataIniFileName);
            var t = data == null?DoNew(dataIniFileName) : DoExisting(data, dataIniFileName);

            t.GetAwaiter().GetResult();
        }