* @return this
     */
    public Request with(Object... args) {
       if (args != null) {
            if (args.length % 2 != 0) throw new IllegalArgumentException("need even number of arguments");
            for (int i = 0; i < args.length; i += 2) {
                add(args[i].toString(), args[i + 1]);
            }
       }
       return this;
    }