protected override void Initialize(RequestContext requestContext)
        {
            base.Initialize(requestContext);

            UserState userState = new UserState();

            if (User is ClaimsPrincipal)
            {
                var user            = User as ClaimsPrincipal;
                var claims          = user.Claims.ToList();
                var userStateString = GetClaim(claims, "UserState");

                if (!string.IsNullOrEmpty(userStateString))
                {
                    userState.FromString(userStateString);
                    Session["UserState"] = userState;
                }
            }
        }