/**
  * Constructor
  */
 public function __construct()
 {
     $this->addedNodes = new \SplObjectStorage();
     $this->removedNodes = new \SplObjectStorage();
     parent::__construct();
 }
 /**
  * Constructor
  */
 public function __construct()
 {
     parent::__construct();
     $this->removedResources = new \SplObjectStorage();
     $this->addedResources = new \SplObjectStorage();
 }