docs: private Path[] getPaths(final Series<X, Y> SERIES) {
              if (!getData().contains(SERIES)) { return null; }
  
              Node seriesNode = SERIES.getNode();
              if (null == seriesNode) { return null; }
  
              Group seriesGroup = (Group) seriesNode;
              if (seriesGroup.getChildren().isEmpty() || seriesGroup.getChildren().size() < 2) { return null; }
  
          return new Path[] { /* FillPath   */ (Path) (seriesGroup).getChildren().get(0),
                              /* StrokePath */ (Path) (seriesGroup).getChildren().get(1) };
      }