//@Override
        protected override string constructKey(HttpRequest request)
        {
            string username = request.getParameter(this.getUsernameParameter());

            if (username == null)
            {
                return request.getRemoteAddr();
            }

            return request.getRemoteAddr() + ";" + username.ToLower();
        }
 //@Override
 protected override string constructKey( HttpRequest request) {
     return request.getRemoteAddr();
 }