factory configurator calls in service container

Factory to Create Services
https://symfony.com/doc/current/service_container/factories.html

Service Method Calls and Setter Injection
Usually, you'll want to inject your dependencies via the constructor. But sometimes, especially if a dependency is optional, you may want to use "setter injection". For example:
To configure the container to call the setLogger method, use the calls key:https://symfony.com/doc/current/service_container/calls.html

Configure a Service with a Configurator
The service configurator is a feature of the service container that allows you to use a callable to configure a service after its instantiation.