protected function loadSwiftMailer(array $config, ContainerBuilder $container)
    {
        $def = new Definition($container->getParameter('snc_redis.swiftmailer_spool.class'));
        $def->setPublic(false);
        $def->addMethodCall('setRedis', array(new Reference(sprintf('snc_redis.%s', $config['swiftmailer']['client']))));
        $def->addMethodCall('setKey', array($config['swiftmailer']['key']));
        $container->setDefinition('snc_redis.swiftmailer.spool', $def);
        $container->setAlias('swiftmailer.spool.redis', 'snc_redis.swiftmailer.spool');
    }