Symfony 4，如何从自定义服务类中获取services.yaml参数？ （在构造函数中没有注入ParameterBagInterface）

From a custom service Class, I can easily get an argument defined in the services.yaml file by inject the service ParameterBagInterface in the constructor of my service class like this :

#from the services.yaml
...
services:
...
    App\Utils\myCustomService:
        arguments:
            $faa: 'some value'
...

//from my custom service Class
...
public function __construct(ParameterBagInterface $faa){
    dump($faa); //print 'some value';
}

But for some reason, I want use a 'normal' parameter in the constructor of my service like this :

//from my custom service Class
...
public function __construct($aNormalParameter){
    // do some stuff with $aNormalParameter
    // but I also want to work with the $faa value located in the services.yaml file, how can I do that ? 
}

//from a custom Controller
...
public function home(){
    $myCustomService = new App\Utils\myCustomService("blabla");
}

So my question, how can I access to an argument I defined in the services.yaml file without inject the ParameterBagInterface service in the constructor ?

Thank you :)