public function isOwner($email, $groupId)
    {
        $uri  = self::APPS_BASE_FEED_URI . self::APPS_GROUP_PATH . '/';
        $uri .= $this->getDomain() . '/' . $groupId . '/owner/' . $email;

        //if the enitiy is not an owner of the group, an exception is thrown
        try {
            $results = $this->get($uri);
        } catch (Exception $e) {
            $results = false;
        }

        if($results) {
            return TRUE;
        } else {
            return FALSE;
        }
    }