code: @Deprecated
      void addSublist(JFXListView<?> subList, int index) {
          if (!sublistsProperty.get().contains(subList)) {
              sublistsProperty.get().add(subList);
              sublistsIndices.put(index, subList);
              subList.getSelectionModel().selectedIndexProperty().addListener((o, oldVal, newVal) -> {
                  if (newVal.intValue() != -1) {
                      updateOverAllSelectedIndex();
                  }
              });
          }
      }
docs: this method shouldn't be called from user