protected function identifierToGroupID($groupID)
    {
        if (is_numeric($groupID) && Group::get()->byID($groupID)) {
            return $groupID;
        } elseif (is_string($groupID) && $groupByCode = Group::get()->filter(['Code' => $groupID])->first()) {
            return $groupByCode->ID;
        } elseif ($groupID instanceof Group && $groupID->exists()) {
            return $groupID->ID;
        }
        return null;
    }