public static String validateCanal(final Route route,final Collection<Unit> units,final PlayerID player,final GameData data){
  for (  final Territory routeTerritory : route.getAllTerritories()) {
    final Optional<String> result=validateCanal(routeTerritory,route,units,player,data);
    if (result.isPresent()) {
      return result.get();
    }
  }
  return null;
}

public static String validateCanal ( final Route route , final Collection < Unit > units , final PlayerID player , final GameData data ) { for ( final Territory routeTerritory : route . getAllTerritories ( ) ) { final Optional < String > result = validateCanal ( routeTerritory , route , units , player , data ) ; if ( result . isPresent ( ) ) { return result . get ( ) ; } } return null ; }
test a route ' s canals to see if you can move through it .
