public function retrieveAllEntriesForFeed($feed) {
        $feedClass = get_class($feed);
        $reflectionObj = new ReflectionClass($feedClass);
        $result = $reflectionObj->newInstance();
        do {
            foreach ($feed as $entry) {
                $result->addEntry($entry);
            }

            $next = $feed->getLink('next');
            if ($next !== null) {
                $feed = $this->getFeed($next->href, $feedClass);
            } else {
                $feed = null;
            }
        }
        while ($feed != null);
        return $result;
    }