services:
    service_container:
        class: Symfony\Component\DependencyInjection\ContainerInterface
        synthetic: true
    foo:
        class: Class1
        arguments: [!service { class: Class2, arguments: [!service { class: Class2 }] }]
    Psr\Container\ContainerInterface:
        alias: service_container
        public: false
    Symfony\Component\DependencyInjection\ContainerInterface:
        alias: service_container
        public: false