Symfony2 caching with LiipDoctrineCacheBundle

config.yml

liip_doctrine_cache:
    namespaces:
        mynamespace:
            namespace: mynamespace.cache
            type: php_file

IndexController.php

$cache = $container->get('liip_doctrine_cache.ns.[mynamespace]');
if (false === ($cached_data = $cache->fetch($cache_key))) {
            $cached_data = $SOMEAPI->getData($params);
            $cache->save($cache_key, $cached_data, 3600);//TTL 1h
}