docs: private void addExternalResourceTags(StringBuffer sb, CmsContentDefinition definition) {
  
          Set<String> includedScripts = new HashSet<String>();
          Set<String> includedStyles = new HashSet<String>();
          for (CmsExternalWidgetConfiguration configuration : definition.getExternalWidgetConfigurations()) {
              for (String css : configuration.getCssResourceLinks()) {
                  // avoid including the same resource twice
                  if (!includedStyles.contains(css)) {
                      sb.append("<link type=\"text/css\" rel=\"stylesheet\" href=\"").append(css).append("\"></link>");
                      includedStyles.add(css);
                  }
              }
              for (String script : configuration.getJavaScriptResourceLinks()) {
                  // avoid including the same resource twice
                  if (!includedScripts.contains(script)) {
                      sb.append("<script type=\"text/javascript\" src=\"").append(script).append("\"></script>");
                      includedScripts.add(script);
                  }
              }
          }
      }