default:
                        throw new AssertionError();
                }
                if (DEBUG) System.err.println(" - new with idx "+idx);
                LatLon center = bbox.getCenter();
                BBox b = new BBox(lon1,lat1, center.lon(), center.lat());
                children[idx] = new GPLevel<>(level + 1, b, this, owner);
            }
            return children[idx].getBounded(ll);
        }