code: private void renderEFapsHeaderItems()
      {
          Collections.sort(this.eFapsHeaderItems, (_item0, _item1) -> _item0.getSortWeight().compareTo(_item1.getSortWeight()));
  
          final List<String> css = new ArrayList<>();
          final List<String> js = new ArrayList<>();
          for (final AbstractEFapsHeaderItem item : this.eFapsHeaderItems) {
              if (item instanceof EFapsJavaScriptHeaderItem) {
                  js.add(item.getReference().getName());
              } else {
                  css.add(item.getReference().getName());
              }
          }
          try {
              if (!css.isEmpty()) {
                  final String key = BundleMaker.getBundleKey(css, TempFileBundle.class);
                  final TempFileBundle bundle = (TempFileBundle) BundleMaker.getBundle(key);
                  bundle.setContentType("text/css");
                  super.render(CssHeaderItem.forUrl(EFapsApplication.get().getServletContext()
                                  .getContextPath() + "/servlet/static/" + key));
              }
              if (!js.isEmpty()) {
                  final String key = BundleMaker.getBundleKey(js, TempFileBundle.class);
                  final TempFileBundle bundle = (TempFileBundle) BundleMaker.getBundle(key);
                  bundle.setContentType("text/javascript");
                  super.render(JavaScriptHeaderItem.forUrl(EFapsApplication.get().getServletContext()
                                  .getContextPath() + "/servlet/static/" + key));
              }
          } catch (final EFapsException e) {
              EFapsResourceAggregator.LOG.error("Error on rendering eFaps Header items: ", e);
          }
      }
docs: render the eFaps Resource items.