code: public void loadSettingValues() {
      PreferencesFxUtils.categoriesToSettings(flatCategoriesLst)
          .forEach(setting -> {
            LOGGER.trace("Loading: " + setting.getBreadcrumb());
            if (saveSettings) {
              setting.loadSettingValue(storageHandler);
            }
            history.attachChangeListener(setting);
          });
    }
docs: Load all of the values of the settings using a {@link StorageHandler} and attaches a listener
  for {@link History}, so that it will be notified of changes to the setting's values.