/**
  * Clear the instance pool.
  *
  * @return     void
  */
 public static function clearInstancePool()
 {
     foreach (self::$instances as $instance) {
         $instance->clearAllReferences(false);
     }
     self::$instances = array();
 }
 /**
  * Clear the instance pool.
  *
  * @return     void
  */
 public static function clearInstancePool()
 {
     self::$instances = array();
 }