public function extend(Application $app)
{
$class = $this->class;
Notification::registerType($class);
User::registerPreference(User::notificationPreferenceKey($class::getType(), 'alert'), 'boolval', in_array('alert', $this->enabled));
if ($class::isEmailable()) {
User::registerPreference(User::notificationPreferenceKey($class::getType(), 'email'), 'boolval', in_array('email', $this->enabled));
}
NotificationSerializer::$subjects[$class::getType()] = $this->serializer;
}