/**
* 类静态构造实例的唯一入口
* @params object app object
* @params object model object
* @return object b2c_order_reship的对象
*/
public static function getInstance($app, $model)
{
if (is_object(self::$instance)) {
return self::$instance;
}
self::$instance = new b2c_order_reship($app, $model);
return self::$instance;
}