@Override
  public void execute() throws IOException {
    super.execute();

    for (OsmStreamOutput output : outputs.values()) {
      output.getOsmOutput().complete();
      output.close();
    }
  }
 @Override
 protected void process(OsmWay way, Node leaf) throws IOException {
   OsmStreamOutput output = outputs.get(leaf);
   output.getOsmOutput().write(way);
 }