static MultiPolygon multipolygon(List<List<CoordinateSequence>> list) {
    return GeoUtils.createMultiPolygon(map(list, GeoArrow::polygon));
  }
Utilities for converting nested <a href=
"https://github.com/opengeospatial/geoparquet/blob/main/format-specs/geoparquet.md#native-encodings-based-on-geoarrow">geoarrow</a>
coordinate lists to JTS geometries.
planetiler-core/src/main/java/com/onthegomap/planetiler/reader/parquet/GeoArrow.java