//XXX: revert to underscore because of that shit:
                        //XXX: see https://symfony.com/doc/current/components/config/definition.html#normalization
                        //XXX: see https://github.com/symfony/symfony/issues/7405
                        //XXX: revert to underscore because of that shit:
                        //XXX: see https://symfony.com/doc/current/components/config/definition.html#normalization
                        //XXX: see https://github.com/symfony/symfony/issues/7405