code: private void checkTransitives(Tile neighbor, String group, GroupTransition current, TileRef ref)
      {
          if (!group.equals(current.getOut())
              && TransitionType.CENTER == mapTransition.getTransition(ref, current.getOut()).getType())
          {
              map.setTile(map.createTile(ref.getSheet(), ref.getNumber(), neighbor.getX(), neighbor.getY()));
          }
      }
docs: Check transitive tiles.
  
  @param neighbor The current neighbor.
  @param group The current group.
  @param current The current transition.
  @param ref The tile ref to check.