code: private void createCheckboxes() {
      node.getChildren().clear();
      checkboxes.clear();
  
      for (int i = 0; i < field.getItems().size(); i++) {
        CheckBox cb = new CheckBox();
  
        cb.setText(field.getItems().get(i).toString());
        cb.setSelected(field.getSelection().contains(field.getItems().get(i)));
  
        checkboxes.add(cb);
      }
  
      node.getChildren().addAll(checkboxes);
    }
docs: This method creates node and adds them to checkboxes and is
  used when the itemsProperty on the field changes.