@Override
  protected PortletPreferences doDeleteData(
      PortletDataContext portletDataContext,
      String portletId,
      PortletPreferences portletPreferences)
      throws Exception {

    if (!portletDataContext.addPrimaryKey(CalendarPortletDataHandlerImpl.class, "deleteData")) {

      CalEventLocalServiceUtil.deleteEvents(portletDataContext.getScopeGroupId());
    }

    return null;
  }