function thb_system_admin_url($slug)
 {
     if (thb_system_is_production()) {
         $basepage = 'admin';
     } else {
         $basepage = 'themes';
     }
     return admin_url('/' . $basepage . '.php?page=' . $slug);
 }
 /**
  * Register all the defined theme's administration pages.
  *
  * @return void
  **/
 public function registerPages()
 {
     if (!empty($this->_pages)) {
         $menu_image = null;
         $i = 0;
         foreach ($this->_pages as $page) {
             $page_title = $page->getTitle();
             $page_slug = $page->getSlug();
             $page_capability = $page->getCapability();
             $page_handler = array($page, 'render');
             if (thb_system_is_production()) {
                 if ($i == 0) {
                     add_menu_page($page_title, $page_title, $page_capability, $page_slug, $page_handler, $menu_image, 58);
                     add_submenu_page($page_slug, $page_title, $page_title, $page_capability, $page_slug, $page_handler);
                     $master_page_slug = $page_slug;
                     $i++;
                 } else {
                     add_submenu_page($master_page_slug, $page_title, $page_title, $page_capability, $page_slug, $page_handler);
                 }
             } else {
                 add_theme_page($page_title, $page_title, $page_capability, $page_slug, $page_handler);
             }
         }
     }
 }