public function setAdditionalCookie($cookie, $expectedValue = false)
    {
        $additionalCookie = $this->_getData('_additional_cookie');
        if (!$additionalCookie || !is_array($additionalCookie)) {
            $additionalCookie = array();
        }

        $additionalCookie[$cookie] = $expectedValue;
        $this->setData('_additional_cookie', $additionalCookie);
        return $this;
    }