public function shouldAddJs($status, $headers)
    {
        return
            $status == 200 &&
            $this->isHtml($headers) &&
            !$this->hasAttachment($headers);
            
            /**
             * @todo not sure if below two conditions will be applicable
             */
            /* !env[JS_IS_INJECTED_KEY] */
            /* && !streaming?(env) */
    }