/**
  * Constructor
  */
 public function __construct()
 {
     parent::__construct();
     $this->_name = __('Select Box Link Image');
     $this->_required = true;
     $this->_showassociation = true;
 }
 public function __construct(&$parent)
 {
     parent::__construct($parent);
     $this->_name = 'Reference Link';
 }