@Override
  protected Geometry transformPolygon(Polygon geom, Geometry parent) {
    return geom.isEmpty() ? null : super.transformPolygon(geom, parent);
  }
Apply a penalty from {@code k=0} to {@code k=1} to drop more sharp corners from the resulting geometry.
<p>
{@code k=0} is the default to apply no penalty for corner sharpness and just drop based on effective triangle area
at the vertex. {@code k=0.7} is the recommended setting to drop corners based on weighted effective area.
planetiler-core/src/main/java/com/onthegomap/planetiler/geo/VWSimplifier.java