@Test
  void testIgnoreSingleNotClosed() throws GeometryException {
    testBuildMultipolygon(
      List.of(
        rectangleNodes(0, 10),
        List.of(
          node(20, 20),
          node(30, 20),
          node(30, 30),
          node(20, 30)
        // not closed
        )
      ),
      rectangle(0, 10)
    );
  }
This class is ported to Java from https://github.com/omniscale/imposm3/blob/master/geom/multipolygon_test.go
planetiler-core/src/test/java/com/onthegomap/planetiler/reader/osm/OsmMultipolygonTest.java