protected function processDefinition($locale, array $definition)
    {
        $definition['locale'] = $locale;
        // The generation script strips all keys that have the same values
        // as the ones in 'en'.
        if ($definition['locale'] != 'en') {
            $definitions = $this->getDefinitions();
            $definition += $definitions['en'];
        }

        return $definition;
    }