private function addRedisNode()
    {
        $builder = new TreeBuilder();
        $node = $builder->root('redis');

        $node
            ->addDefaultsIfNotSet()
            ->children()
                ->scalarNode('connection_id')->defaultNull()->end()
                ->scalarNode('host')->defaultValue('127.0.0.1')->end()
                ->scalarNode('port')->defaultValue('6379')->end()
                ->scalarNode('password')->defaultNull()->end()
                ->scalarNode('timeout')->defaultNull()->end()
                ->scalarNode('database')->defaultNull()->end()
            ->end();

        return $node;
    }