protected WizardPopup createPopup(WizardPopup parent, PopupStep step, Object parentValue) {
    if (step instanceof ListPopupStep) {
      return new ListPopupImpl(getProject(), parent, (ListPopupStep)step, parentValue);
    }
    else if (step instanceof TreePopupStep) {
      return new TreePopupImpl(getProject(), parent, (TreePopupStep)step, parentValue);
    }
    else {
      throw new IllegalArgumentException(step.getClass().toString());
    }
  }
protected WizardPopup createPopup(WizardPopup parent, PopupStep step, Object parentValue)