public double progressOnLevel(TileCoord coord, TileExtents extents) {
    return progressOnLevel.applyAsDouble(coord, extents);
  }
Controls the sort order of {@link com.onthegomap.planetiler.collection.FeatureGroup}, which determines the ordering
of {@link com.onthegomap.planetiler.archive.TileEncodingResult}s when written to
{@link WriteableTileArchive.TileWriter}.
planetiler-core/src/main/java/com/onthegomap/planetiler/geo/TileOrder.java