public function __construct(array $manifest)
 {
     parent::__construct($manifest);
     unset($manifest);
     // unset unnecessary keys
     unset($this->manifest['id']);
     $this->manifest = array_merge(array('display' => false, 'standalone' => false, 'thumbnail' => null), $this->manifest);
 }
 public function __construct(array $manifest)
 {
     parent::__construct($manifest);
     unset($manifest);
     // unset unnecessary keys
     unset($this->manifest['id']);
 }