/**
  * Initialise the {@link SiteNavigation} object
  *
  * The {@link SiteNavigation} object implements a Singleton pattern, and controls
  * the access to navigation items, as well as the process of printing them to the
  * output.
  * @param force_reload - reload the navigation item even if one is already registered
  */
 public function siteNavigationInit($force_reload = false)
 {
     if (!SiteNavigation::ready() || $force_reload) {
         $ret = SiteNavigation::init($this->user->getHandlerTree());
     } else {
         $ret = SiteNavigation::current();
     }
     return $ret;
 }