code: private boolean notifyOnFinish() {
          boolean result = true;
          NavigationPreference selectedNavigationPreference =
                  navigationFragment.getSelectedNavigationPreference();
  
          if (selectedNavigationPreference != null && preferenceFragment != null) {
              for (WizardListener listener : wizardListeners) {
                  result &= listener.onFinish(selectedNavigationPreference, preferenceFragment,
                          selectedPreferenceFragmentArguments);
              }
          }
  
          return result;
      }
docs: Notifies all registered listeners that the user wants to finish the last step of the wizard.
  
  @return True, if finishing the wizard should be allowed, false otherwise