public function generateIdentifier(NotifiableInterface $notifiable)
    {
        $Notifiableidentifiers = $this->getNotifiableIdentifier($notifiable);
        $identifierValues = array();
        foreach ($Notifiableidentifiers as $identifier) {
            $method = sprintf('get%s', ucfirst($identifier));
            $identifierValues[] = $notifiable->$method();
        }

        return implode('-', $identifierValues);
    }