private int upgradeForGood(Service type) {
    final Integer key = (Integer) SupplyDepot.SERVICE_KEY.get(type) ;
    final Upgrade KU ;
    if (key == null) return -1 ;
    else if (key == SupplyDepot.KEY_RATIONS ) KU = RATIONS_STOCK      ;
    else if (key == SupplyDepot.KEY_MINERALS) KU = PROSPECT_EXCHANGE  ;
    else if (key == SupplyDepot.KEY_MEDICAL ) KU = MEDICAL_EXCHANGE   ;
    else if (key == SupplyDepot.KEY_BUILDING) KU = HARDWARE_STOCK     ;
    else return -1 ;
    return structure.upgradeLevel(KU) ;
  }