public function getRecipientSpecificNotificationsSubject($contentItems, RecipientInterface $recipient)
    {
        $count = sizeof($contentItems);

        if (1 == $count) {
            // get the content-item out of the boxed associative array => array(array('templateId' => contentItem))
            $onlyItem = current(current($contentItems));
            // get the title out of the notification in the contentItem
            return $onlyItem['notification']->getTitle();
        }

        return $this->translatorService->transChoice('_az.email.notifications.subject.%count%', $count, array('%count%' => $count));
    }