public Feature centroidIfConvex(String layer) {
    try {
      return geometry(layer, source.centroidIfConvex());
    } catch (GeometryException e) {
      e.log(stats, "feature_centroid_if_convex", "Error constructing centroid if convex for " + source);
      return empty(layer);
    }
  }
Starts building a new point map feature with geometry from {@link Geometry#getCentroid()} if the source feature is
a point, line, or simple convex polygon, or {@link Geometry#getInteriorPoint()} if it is a multipolygon, polygon
with holes, or concave simple polygon.

@param layer the output vector tile layer this feature will be written to
@return a feature that can be configured further.
planetiler-core/src/main/java/com/onthegomap/planetiler/FeatureCollector.java