// GET: CustomTab
        public ActionResult Index()
        {
            var model = new CustomTabModel(_Common, HttpContext);

            model.HasToken = TokenProvider.HasAccessToken();
            return(View(model));
        }
        public async Task <ActionResult> SignIn()
        {
            var model = new CustomTabModel(_Common, HttpContext);

            model.HasToken = TokenProvider.HasAccessToken();
            if (model.HasToken)
            {
                return(View("Index", model));
            }

            try
            {
                var token = await TokenProvider.GetUserAccessTokenAsync();
            }
            catch
            {
                model.Message = "Please Login";
                return(View());
            }

            return(RedirectToAction("Index"));
        }