docs: public Map<String, Set<?>> getRegistry(final IPerson user, final PortletRequest req) {
  
          Map<String, Set<?>> registry = new TreeMap<String, Set<?>>();
  
          // Empty, or the set of categories that are permitted to
          // be displayed in the Portlet Marketplace (portlet)
          final Set<PortletCategory> permittedCategories = getPermittedCategories(req);
  
          final Set<MarketplaceEntry> visiblePortlets =
                  this.marketplaceService.browseableMarketplaceEntriesFor(user, permittedCategories);
  
          final Set<PortletCategory> visibleCategories =
                  this.marketplaceService.browseableNonEmptyPortletCategoriesFor(
                          user, permittedCategories);
  
          final Set<MarketplaceEntry> featuredPortlets =
                  this.marketplaceService.featuredEntriesForUser(user, permittedCategories);
  
          registry.put("portlets", visiblePortlets);
          registry.put("categories", visibleCategories);
          registry.put("featured", featuredPortlets);
  
          return registry;
      }