}

    protected void storeStateInSession(final HttpSession session, final String state, final String nonce) {
        @SuppressWarnings("unchecked")
        Map<String, StateData> stateMap = (Map<String, StateData>) session.getAttribute(STATES);
        if (stateMap == null) {
            stateMap = new HashMap<>();
            session.setAttribute(STATES, stateMap);
        }