public function lastChangeUser(): string
    {
        $chan = $this->facts(['CHAN'])->first();

        if ($chan === null) {
            return I18N::translate('Unknown');
        }

        $chan_user = $chan->attribute('_WT_USER');
        if ($chan_user === '') {
            return I18N::translate('Unknown');
        }

        return $chan_user;
    }