code: public PreferencesFx saveSettings(boolean save) {
      preferencesFxModel.setSaveSettings(save);
      // if settings shouldn't be saved, clear them if there are any present
      if (!save) {
        preferencesFxModel.getStorageHandler().clearPreferences();
      }
      return this;
    }
docs: Defines whether the adjusted settings of the application should be saved or not.
  
  @param save if true, the values of all settings of the application are saved. When the
  application is started again, the settings values will be restored to the last
  saved state. Defaults to false.
  @return this object for fluent API