public List<RequestObject> makeRequest(RequestObject request) {
    List<RequestObject> a = new ArrayList<>();

    for (TileLayer layer : layers) a.addAll(layer.callRequest(request));

    return a;
  }
 public void removeLayer(TileLayer layer) {
   if (this.layers.remove(layer)) layer.removedFrom(this);
   logger.setTileChanged(this);
 }
 public void addLayer(TileLayer layer) {
   if (this.layers.add(layer)) layer.addedTo(this);
   sortLayers();
   logger.setTileChanged(this);
 }