public function findByUri($uri, $create = false)
    {
        $subscriber = $this->findOneBy(array( "uri" => $uri ));
        if (!isset($subscriber) && $create) {
            $subscriber = $this->create();
            $subscriber->uri = $uri;
            $this->dm->persist($subscriber);
            $this->dm->flush();
        }
        return $subscriber;
    }