public function getNextFeed($feed, $className = null)
    {
        $nextLink = $feed->getNextLink();
        if (!$nextLink) {
            return null;
        }
        $nextLinkHref = $nextLink->getHref();

        if ($className === null) {
            $className = get_class($feed);
        }

        return $this->getFeed($nextLinkHref, $className);
    }