To manually define a service locator, create a new service definition and add

the ``container.service_locator`` tag to it. Use its ``arguments`` option to

include as many services as needed in it.

the ``container.service_locator`` tag to it. Use the first argument of the

service definition to pass a collection of services to the service locator. If

there is no id specified for the service it will inherit its external id.

..configuration-block::

..versionadded::4.1

The service locator autoconfiguration was introduced in Symfony 4.1. In

previous Symfony versions you always needed to add the

``container.service_locator`` tag explicitly.

..versionadded::4.2

The ability to add services without specifying an id was introduced in

Symfony 4.2.

..note::

The services defined in the service locator argument must include keys,