docs: protected String verifyPortletWindowId(
              HttpServletRequest request, IPortletWindowId portletWindowId) {
          final IUserInstance userInstance = this.userInstanceManager.getUserInstance(request);
          final IUserPreferencesManager preferencesManager = userInstance.getPreferencesManager();
          final IUserLayoutManager userLayoutManager = preferencesManager.getUserLayoutManager();
  
          final IPortletWindow portletWindow =
                  this.portletWindowRegistry.getPortletWindow(request, portletWindowId);
          final IPortletWindowId delegationParentWindowId = portletWindow.getDelegationParentId();
          if (delegationParentWindowId != null) {
              return verifyPortletWindowId(request, delegationParentWindowId);
          }
  
          final IPortletEntity portletEntity = portletWindow.getPortletEntity();
          final String channelSubscribeId = portletEntity.getLayoutNodeId();
          final IUserLayoutNodeDescription node = userLayoutManager.getNode(channelSubscribeId);
          if (node == null) {
              throw new IllegalArgumentException(
                      "No layout node exists for id "
                              + channelSubscribeId
                              + " of window "
                              + portletWindowId);
          }
  
          return node.getId();
      }