docs: public static ScalesResult getScalesResult(final Relation<? extends SpatialComparable> rel) {
      Collection<ScalesResult> scas = ResultUtil.filterResults(rel.getHierarchy(), rel, ScalesResult.class);
      if(scas.isEmpty()) {
        final ScalesResult newsca = new ScalesResult(rel);
        ResultUtil.addChildResult(rel, newsca);
        return newsca;
      }
      return scas.iterator().next();
    }