@Test
  void testBrokenPolygonSelfIntersect1() throws GeometryException {
    Node startEnd = node(0, 0);
    testBuildMultipolygon(
      List.of(
        List.of(
          startEnd,
          node(0, 10),
          node(10, 10),
          node(10, 0),
          node(20, 0),
          node(20, 10),
          node(30, 10),
          node(30, 0),
          startEnd
        ),
        rectangleNodes(2, 8)
      ),
      newPolygon(
        newCoordinateList(
          0, 0,
          0, 10,
          10, 10,
          10, 0,
          20, 0,
          20, 10,
          30, 10,
          30, 0,
          0, 0
        ),
        List.of(
          rectangleCoordList(2, 8)
        )
      )
    );
  }
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