public function toXml(FeedChannel $channel)
{
$this->checkWorkers();
$itemsXml = null;
$itemWorker = $this->getItemWorker();
foreach ($channel->getFeedItems() as $feedItem) {
$itemsXml .= $itemWorker->toXml($feedItem);
}
return $this->getChannelWorker()->toXml($channel, $itemsXml);
}
