I am using edusoho. It is developed based on symfony2. There is a service folder in it that provides operations on the database (not the service in the configuration file in symfony2). This service is not a bundle and is not in registerBundles. Registration is actually a lot of folders containing custom classes. I want to use $this->get in this custom class to obtain services just like using $this->get in the controller. How to do it? Woolen cloth?