/**
  * Get (and instantiate, if necessary) the instance of the class
  * @static
  * @return Shared_Sidebars
  */
 public static function get_instance()
 {
     if (!is_a(self::$instance, __CLASS__)) {
         self::$instance = new self();
     }
     return self::$instance;
 }
function acfw_widget_factory_load()
{
    $GLOBALS['wp_widget_factory'] = ACFW_Widget_Factory::get_instance();
}