docs: @Override
      public IPortletWindowId getPortletForFolderName(
              HttpServletRequest request, String targetedLayoutNodeId, String folderName) {
          final IUserInstance userInstance = this.userInstanceManager.getUserInstance(request);
  
          final String fname;
          final IPortletEntity portletEntity;
  
          final int seperatorIndex = folderName.indexOf(PORTLET_PATH_ELEMENT_SEPERATOR);
          if (seperatorIndex <= 0 || seperatorIndex + 1 == folderName.length()) {
              fname = folderName;
              portletEntity =
                      this.portletEntityRegistry.getOrCreatePortletEntityByFname(
                              request, userInstance, fname);
          } else {
              fname = folderName.substring(0, seperatorIndex);
              final String subscribeId = folderName.substring(seperatorIndex + 1);
  
              portletEntity =
                      this.portletEntityRegistry.getOrCreatePortletEntityByFname(
                              request, userInstance, fname, subscribeId);
          }
          if (portletEntity != null) {
              final IPortletEntityId portletEntityId = portletEntity.getPortletEntityId();
              final IPortletWindow portletWindow =
                      this.portletWindowRegistry.getOrCreateDefaultPortletWindow(
                              request, portletEntityId);
              return portletWindow.getPortletWindowId();
          } else {
              this.logger.warn(
                      targetedLayoutNodeId
                              + " node for portlet of folder "
                              + folderName
                              + " can't be targeted by the request.");
              return null;
          }
      }