/**
* Retrieve previous set of results based on a given feed.
*
* @param \ZendGData\App\Feed $feed The feed from which to
* retreive the previous set of results.
* @param string $className (optional) The class of feed to be returned.
* If null, the previous feed (if found) will be the same class as
* the feed that was given as the first argument.
* @return \ZendGData\App\Feed|null Returns a
* ZendGData\App\Feed or null if no previous set of results
* exists.
*/
public function getPreviousFeed($feed, $className = null)
{
$previousLink = $feed->getPreviousLink();
if (!$previousLink) {
return null;
}
$previousLinkHref = $previousLink->getHref();
if ($className === null) {
$className = get_class($feed);
}
return $this->getFeed($previousLinkHref, $className);
}
