public GeometryPipeline getScaledGeometryTransformAtZoom(int zoom) {
      return ZoomFunction.applyOrElse(geometryPipelineByZoom, zoom, defaultGeometryPipeline);
    }
Returns the geometry transform function to apply to scaled geometries at {@code zoom}, or null to not update them
at all.
planetiler-core/src/main/java/com/onthegomap/planetiler/FeatureCollector.java