public static function extract(array $content, Translations $translations)
    {
        $messages = \current($content);
        $headers = $messages[''] ?? null;
        unset($messages['']);

        if (!empty($headers['domain'])) {
            $translations->setDomain($headers['domain']);
        }

        if (!empty($headers['lang'])) {
            $translations->setLanguage($headers['lang']);
        }

        if (!empty($headers['plural-forms'])) {
            $translations->setHeader(Translations::HEADER_PLURAL, $headers['plural-forms']);
        }

        $context_glue = '\u0004';

        foreach ($messages as $key => $translation) {
            $key = \explode($context_glue, $key);
            $context = isset($key[1]) ? \array_shift($key) : '';

            $translations->insert($context, \array_shift($key))
                ->setTranslation(\array_shift($translation))
                ->setPluralTranslations($translation);
        }
    }