private Optional<String> checkValidity(TileCoord coord, List<VectorTile.Feature> features) {
    for (var feature : features) {
      try {
        Geometry geometry = feature.geometry().decode();
        if (!isValid(geometry)) {
          return Optional.of(coord + "/" + feature.layer());
        }
      } catch (GeometryException e) {
        return Optional.of(coord + " error decoding " + feature.layer() + "feature");
      }
    }
    return Optional.empty();
  }
Exits with a nonzero exit code if there were any failures.
planetiler-core/src/main/java/com/onthegomap/planetiler/mbtiles/Verify.java