public function setHttpStatusCode($code)
    {
        $code = intval($code);
        if (!is_int($code)
            || $code < 100
            || $code > 599
        ) {
            trigger_error('Invalid HTTP status code, not taken into account.', E_USER_WARNING);
            return false;
        }
        $this->httpStatusCode = $code;
        return true;
    }