hack to use a translator that will return keys

gistfile1.php

<?php

// in config : <parameter key="translator.class">AppBundle\Translation\TestTranslator</parameter>
namespace AppBundle\Translation;

use Symfony\Component\Translation\Translator;

class TestTranslator extends Translator
{
    /**
     * @inheritDoc
     */
    public function trans($id, array $parameters = array(), $domain = null, $locale = null)
    {
        return $id;
    }

    /**
     * @inheritDoc
     */
    public function transChoice($id, $number, array $parameters = array(), $domain = null, $locale = null)
    {
        return $id;
    }
}