code: public static Pair<Pane, AbstractFXController> loadFxmlPaneAndControllerPair(final String fxmlFileUri, final Class clazz, final Callback<Class<?>, Object> controllerFactory) throws CouldNotPerformException {
          return loadFxmlPaneAndControllerPair(fxmlFileUri, AbstractFXController.class, clazz, controllerFactory);
      }
docs: Method load the pane and controller of the given fxml file.
  
  @param fxmlFileUri       the uri pointing to the fxml file within the classpath.
  @param clazz             the responsible class which is used for class path resolution.
  @param controllerFactory the controller factory to use. Can be null if the default one should be used.
  
  @return an pair of the pane and its controller.
  
  @throws CouldNotPerformException is thrown if something went wrong like for example the fxml file does not exist.