public void ConfigureAuth(IAppBuilder app)
        {
            TokenCacheDataContext db = new TokenCacheDataContext();

            app.SetDefaultSignInAsAuthenticationType(CookieAuthenticationDefaults.AuthenticationType);

            app.UseCookieAuthentication(new CookieAuthenticationOptions());

            app.UseOpenIdConnectAuthentication(
                new OpenIdConnectAuthenticationOptions
            {
                ClientId              = clientId,
                Authority             = Authority,
                PostLogoutRedirectUri = postLogoutRedirectUri,

                Notifications = new OpenIdConnectAuthenticationNotifications()
                {
                    // If there is a code in the OpenID Connect response, redeem it for an access token and refresh token, and store those away.
                    AuthorizationCodeReceived = (context) =>
                    {
                        var code = context.Code;
                        ClientCredential credential       = new ClientCredential(clientId, appKey);
                        string signedInUserID             = context.AuthenticationTicket.Identity.FindFirst(ClaimTypes.NameIdentifier).Value;
                        AuthenticationContext authContext = new AuthenticationContext(Authority, new EfAdalTokenCache(signedInUserID));
                        AuthenticationResult result       = authContext.AcquireTokenByAuthorizationCode(
                            code, new Uri(HttpContext.Current.Request.Url.GetLeftPart(UriPartial.Path)), credential, graphResourceId);

                        return(Task.FromResult(0));
                    }
                }
            });
        }