public function apply_alternative()
 {
     if (isset($_POST['original']) && isset($_POST['alternative'])) {
         require_once NELIOAB_EXP_CONTROLLERS_DIR . '/widget-experiment-controller.php';
         $exp = $_GET['id'];
         $ori = $_POST['original'];
         $alt = $_POST['alternative'];
         if ($ori == $alt) {
             NelioABWidgetExpAdminController::apply_alternative_and_clean($exp);
         } else {
             NelioABWidgetExpAdminController::apply_alternative_and_clean($exp, $alt);
         }
     }
 }