  {
    private static void Main(string[] args)
    {
      const int PORT = 8080;
      var port = args.Length == 0 ? PORT : int.Parse(args[0]);

      var server = new Grpc.Core.Server
      {
        Services = {UserService.BindService(new SampleImpl())},
        Ports = {new ServerPort("localhost", port, ServerCredentials.Insecure)}