if (null == currentUser) { return Collections.EMPTY_LIST; }
    private Collection getPrincipalAuthorities() {        SecureContext context = ((SecureContext) ContextHolder.getContext());        if (null == context) {            return Collections.EMPTY_LIST;        }        Authentication currentUser = context.getAuthentication();        Collection granted = Arrays.asList(currentUser.getAuthorities());        return granted;    }