/**
  * set the group view to use by default for product lists
  *
  * @param string $defaultGroupView the class name of the group view to use by default
  *
  * @return void
  */
 public static function setDefaultGroupView($defaultGroupView = null)
 {
     if (is_null($defaultGroupView) || !in_array($defaultGroupView, self::$groupViews)) {
         foreach (self::$groupViews as $code => $groupView) {
             self::$defaultGroupView = $code;
             return;
         }
         self::addGroupView($defaultGroupView);
     }
     $tmp = array_flip(self::$groupViews);
     self::$defaultGroupView = $tmp[$defaultGroupView];
 }