static function displayTabContentForItem(CommonGLPI $item, $tabnum = 1, $withtemplate = 0)
 {
     if ($item->getType() == __CLASS__) {
         switch ($tabnum) {
             case 1:
                 $item->showValuesByEntity();
                 break;
             case 2:
                 $item->showItems();
                 break;
         }
     }
     return true;
 }