protected function addCommands(ArrayNodeDefinition $node)
    {
        $node
            ->fixXmlConfig('command')
            ->children()
                ->arrayNode('commands')
                ->addDefaultsIfNotSet()
                    ->children()
                        ->scalarNode('rabbitmq_consumer')->defaultValue('rabbitmq:consumer')->end()
                        ->scalarNode('rabbitmq_multiple_consumer')->defaultValue('rabbitmq:multiple-consumer')->end()
                        ->scalarNode('rabbitmq_batch_consumer')->defaultValue('rabbitmq:batch:consumer')->end()
                        ->scalarNode('rabbitmq_rpc_server')->defaultValue('rabbitmq:rpc-server')->end()
                    ->end()
                ->end()
            ->end()
        ;
    }