code: public void addMenuItem(String index, Class<? extends WebPage> linkClass, String langKey, String langDescKey,
              String... authority) {
          addMenuItem(index, linkClass, langKey, langDescKey, null, authority);
      }
docs: Adds a new item to main header navigation where the index defines the name of the index, which should be the
  class name; linkClass defines the class name to be linked to; langKey defines the language key for the text which
  should be displayed and authority defines who is authorized to see the link