public function checkUpdates(FeedSub $feedsub)
{
$request = new HTTPClient();
$feed = $request->get($feedsub->uri);
if (!$feed->isOk()) {
throw new ServerException('FeedSub could not fetch id=' . $feedsub->id . ' (Error ' . $feed->getStatus() . ': ' . $feed->getBody());
}
$feedsub->receive($feed->getBody(), null);
}