function checkSectorAllowedForLoc(SmrSector &$sector, SmrLocation &$location)
{
    if (!$location->isHQ()) {
        return sizeof($sector->getLocations()) < 4 && !$sector->offersFederalProtection();
    } else {
        //HQs are here
        //find a sector where there are no locations yet
        return !$sector->hasLocation();
    }
}