public void addHouseNumbers(List<HouseNumber> HouseNumbers){
  if (HouseNumbers != null) {
    for (    HouseNumber houseNumber : HouseNumbers) {
      addHouseNumber(houseNumber);
    }
  }
}

public void addHouseNumbers ( List < HouseNumber > HouseNumbers ) { if ( HouseNumbers != null ) { for ( HouseNumber houseNumber : HouseNumbers ) { addHouseNumber ( houseNumber ) ; } } }
do a double set : add ( not replace ! ) the house numbers to the current street and for each house numbers : set the current street as the street of the house numbers
