@Override
      public PopupStep<?> onChosen(Object selectedValue, boolean finalChoice) {
        Object element = ((NodeDescriptor<?>)selectedValue).getElement();
        if (element instanceof ConfigurationType) {
          ConfigurationFactory[] factories = ((ConfigurationType)element).getConfigurationFactories();
          if (factories.length == 1) {
            creator.consume(factories[0]);
            return FINAL_CHOICE;
          }
        }
        if (element instanceof ConfigurationFactory) {
          creator.consume((ConfigurationFactory)element);
          return FINAL_CHOICE;
        }
        return super.onChosen(selectedValue, finalChoice);
      }
@Override
      public PopupStep<?> onChosen(Object selectedValue, boolean finalChoice)