docs: @Override
      public void contextDestroyed(ServletContextEvent sce) {
          //destroy the root portlet app context
          final ServletContext servletContext = sce.getServletContext();
          contextLoader.closeWebApplicationContext(servletContext);
          
          servletContext.removeAttribute(PortletApplicationContextUtils2.ROOT_PORTLET_APPLICATION_CONTEXT_LOADER_ATTRIBUTE);
          contextLoader = null;
      }