[Command(Name = "istrada", ThrowOnUnexpectedArgument = false, OptionsComparison = System.StringComparison.InvariantCultureIgnoreCase )]
    [VersionOptionFromMember("--version", MemberName = nameof(GetVersion))]
    [Subcommand(
        typeof(LoginCmd),
        typeof(ListTicketCmd))]
    class iStradaCmd : iStradaCmdBase
    {
        public iStradaCmd(ILogger<iStradaCmd> logger)
        {
            _logger = logger;
        }

        protected override Task<int> OnExecute(CommandLineApplication app)
        {
            // this shows help even if the --help option isn't specified
            app.ShowHelp();
            return Task.FromResult(1);
        }

        private static string GetVersion()
            => typeof(iStradaCmd).Assembly.GetCustomAttribute<AssemblyInformationalVersionAttribute>().InformationalVersion;
    }