private void filterOutInteriorOrExteriorZones(final Set<StendhalRPZone> zonesInRegion,final Boolean exterior){
  final Set<StendhalRPZone> removals=new HashSet<StendhalRPZone>();
  for (  StendhalRPZone zone : zonesInRegion) {
    if (exterior) {
      if (zone.isInterior()) {
        removals.add(zone);
      }
    }
 else {
      if (!zone.isInterior()) {
        removals.add(zone);
      }
    }
  }
  zonesInRegion.removeAll(removals);
}

private void filterOutInteriorOrExteriorZones ( final Set < StendhalRPZone > zonesInRegion , final Boolean exterior ) { final Set < StendhalRPZone > removals = new HashSet < StendhalRPZone > ( ) ; for ( StendhalRPZone zone : zonesInRegion ) { if ( exterior ) { if ( zone . isInterior ( ) ) { removals . add ( zone ) ; } } else { if ( ! zone . isInterior ( ) ) { removals . add ( zone ) ; } } } zonesInRegion . removeAll ( removals ) ; }
filter out exterior or interior zones from the given set
