performNoDeepMerging example

        $treeBuilder = new TreeBuilder('storefront');

        $rootNode = $treeBuilder->getRootNode();

        $rootNode
            ->children()
                ->arrayNode('reverse_proxy')
                    ->children()
                        ->booleanNode('enabled')->end()
                        ->booleanNode('use_varnish_xkey')->defaultFalse()->end()
                        ->arrayNode('hosts')->performNoDeepMerging()->scalarPrototype()->end()->end()
                        ->integerNode('max_parallel_invalidations')->defaultValue(2)->end()
                        ->scalarNode('redis_url')->end()
                        ->scalarNode('ban_method')->defaultValue('BAN')->end()
                        ->arrayNode('ban_headers')->performNoDeepMerging()->defaultValue([])->scalarPrototype()->end()->end()
                        ->arrayNode('purge_all')
                            ->children()
                                ->scalarNode('ban_method')->defaultValue('BAN')->end()
                                ->arrayNode('ban_headers')->performNoDeepMerging()->defaultValue([])->scalarPrototype()->end()->end()
                                ->arrayNode('urls')->performNoDeepMerging()->defaultValue(['/'])->scalarPrototype()->end()->end()
                            ->end()
                        ->end()
                        

->scalarNode('logger_level')->defaultValue($debug ? Level::Debug : Level::Error)->end()
                ->arrayNode('ssl')
                    ->children()
                        ->scalarNode('cert_path')->end()
                        ->scalarNode('cert_password')->end()
                        ->scalarNode('cert_key_path')->end()
                        ->scalarNode('cert_key_password')->end()
                        ->booleanNode('verify_server_cert')->defaultValue(true)->end()
                    ->end()
                ->end()
                ->arrayNode('index_settings')->variablePrototype()->end()->end()
                ->arrayNode('analysis')->performNoDeepMerging()->variablePrototype()->end()->end()
                ->arrayNode('language_analyzer_mapping')->defaultValue([])->scalarPrototype()->end()->end()
                ->arrayNode('dynamic_templates')->performNoDeepMerging()->variablePrototype()->end()->end()
                ->arrayNode('product')
                    ->children()
                        ->arrayNode('custom_fields_mapping')
                            ->variablePrototype()->end()
                        ->end()
                    ->end()
                ->end()
                ->arrayNode('search')
                    ->children()
                        

$rootNode = (new TreeBuilder('filesystem'))->getRootNode();
        $rootNode
            ->children()
                ->arrayNode('private')
                    ->children()
                        ->scalarNode('type')->end()
                        ->scalarNode('visibility')->end()
                        ->variableNode('config')->end()
                    ->end()
                ->end()
                ->arrayNode('public')
                    ->performNoDeepMerging()
                    ->children()
                        ->scalarNode('type')->end()
                        ->scalarNode('url')->end()
                        ->scalarNode('visibility')->end()
                        ->variableNode('config')->end()
                    ->end()
                ->end()
                ->arrayNode('temp')
                    ->performNoDeepMerging()
                    ->children()
                        ->scalarNode('type')->end()
                        

->info('looks for translation in old fashion way')
                            ->setDeprecated('symfony/config', '6.0')
                        ->end()
                    ->end()
                ->end()
                ->arrayNode('messenger')
                    ->children()
                        ->arrayNode('routing')
                            ->normalizeKeys(false)
                            ->useAttributeAsKey('message_class')
                            ->prototype('array')
                                ->performNoDeepMerging()
                                ->fixXmlConfig('sender')
                                ->children()
                                    ->arrayNode('senders')
                                        ->requiresAtLeastOneElement()
                                        ->prototype('scalar')->end()
                                    ->end()
                                ->end()
                            ->end()
                        ->end()
                        ->arrayNode('receiving')
                            ->prototype('array')
                                

$tree->merge($a, $b);
    }

    public function testPerformsNoDeepMerging()
    {
        $tb = new TreeBuilder('root', 'array');

        $tree = $tb
            ->getRootNode()
                ->children()
                    ->node('no_deep_merging', 'array')
                        ->performNoDeepMerging()
                        ->children()
                            ->node('foo', 'scalar')->end()
                            ->node('bar', 'scalar')->end()
                        ->end()
                    ->end()
                ->end()
            ->end()
            ->buildTree()
        ;

        $a = [
            

return $tb;
    }

    private function addRoleHierarchySection(ArrayNodeDefinition $rootNode): void
    {
        $rootNode
            ->fixXmlConfig('role', 'role_hierarchy')
            ->children()
                ->arrayNode('role_hierarchy')
                    ->useAttributeAsKey('id')
                    ->prototype('array')
                        ->performNoDeepMerging()
                        ->beforeNormalization()->ifString()->then(fn ($v) => ['value' => $v])->end()
                        ->beforeNormalization()
                            ->ifTrue(fn ($v) => \is_array($v) && isset($v['value']))
                            ->then(fn ($v) => preg_split('/\s*,\s*/', $v['value']))
                        ->end()
                        ->prototype('scalar')->end()
                    ->end()
                ->end()
            ->end()
        ;
    }

    

->arrayNode('enabled_locales')
                    ->info('Defines the possible locales for the application. This list is used for generating translations files, but also to restrict which locales are allowed when it is set from Accept-Language header (using "set_locale_from_accept_language").')
                    ->prototype('scalar')->end()
                ->end()
                ->arrayNode('trusted_hosts')
                    ->beforeNormalization()->ifString()->then(fn ($v) => [$v])->end()
                    ->prototype('scalar')->end()
                ->end()
                ->scalarNode('trusted_proxies')->end()
                ->arrayNode('trusted_headers')
                    ->fixXmlConfig('trusted_header')
                    ->performNoDeepMerging()
                    ->defaultValue(['x-forwarded-for', 'x-forwarded-port', 'x-forwarded-proto'])
                    ->beforeNormalization()->ifString()->then(fn ($v) => $v ? array_map('trim', explode(',', $v)) : [])->end()
                    ->enumPrototype()
                        ->values([
                            'forwarded',
                            'x-forwarded-for', 'x-forwarded-host', 'x-forwarded-proto', 'x-forwarded-port', 'x-forwarded-prefix',
                        ])
                    ->end()
                ->end()
                ->scalarNode('error_controller')
                    ->defaultValue('error_controller')