public Feature copyWithExtraAttrs(Map<String, Object> extraAttrs) {
      return new Feature(
        layer,
        id,
        geometry,
        Stream.concat(tags.entrySet().stream(), extraAttrs.entrySet().stream())
          .collect(Collectors.toMap(Map.Entry::getKey, Map.Entry::getValue)),
        group
      );
    }
Returns a copy of this feature with {@code extraAttrs} added to {@code attrs}.
planetiler-core/src/main/java/com/onthegomap/planetiler/VectorTile.java