public static void SaveSession(this IHttpRequest httpReq, IAuthSession session, TimeSpan? expiresIn = null)
        {
            if (httpReq == null) return;

            using (var cache = httpReq.GetCacheClient())
            {
                var sessionKey = SessionFeature.GetSessionKey(httpReq.GetSessionId());
                cache.CacheSet(sessionKey, session, expiresIn ?? AuthFeature.GetDefaultSessionExpiry());
            }

            httpReq.Items[RequestItemsSessionKey] = session;
        }