private function addServiceSection(ArrayNodeDefinition $node)
    {
        $node
            ->children()
                ->arrayNode('service')
                    ->addDefaultsIfNotSet()
                    ->children()
                        ->scalarNode('class')
                            ->defaultValue(Service\Queue::class)->cannotBeEmpty()
                        ->end()
                        ->scalarNode('alias')
                            ->defaultValue('queue')->cannotBeEmpty()
                        ->end()
                        ->scalarNode('storage')
                            ->defaultValue('redis')->cannotBeEmpty()
                        ->end()
                    ->end()
                ->end()
            ->end();
    }