docs: private void setHeaders(HttpServletResponse response) {
          setHeader(response, "Expires", Long.valueOf(System.currentTimeMillis() + cacheTimeoutMs).toString()); 
          setHeader(response, "Cache-Control", "public, must-revalidate, max-age=" + cacheTimeout); // HTTP 1.1.
          setHeader(response, "Pragma", "public"); 
      }