public function shareReply($href, $status, $calendarUri, $inReplyTo, $summary = null)
    {
        if (!$this->caldavBackend instanceof Backend\SharingSupport) {
            throw new DAV\Exception\NotImplemented('Sharing support is not implemented by this backend.');
        }

        return $this->caldavBackend->shareReply($href, $status, $calendarUri, $inReplyTo, $summary);
    }