public function setCacheHeaders($expirationTimeInSeconds = 300) {
        $expirationString = strtotime("+{$expirationTimeInSeconds} seconds");
        $gmtDate = gmdate(DATE_RFC1123, $expirationString);

        $this->getResponse()
            ->setHeader('Cache-Control', 'public', true)
            ->setHeader('Pragma', 'cache', true)
            ->setHeader('Expires', $gmtDate, true);
    }