private static function processObsoleteEntry(
        ?string $lastPreviousKey,
        ?string $tmpKey,
        string $str,
        array $entry
    ): array {
        $entry['obsolete'] = true;

        switch ($tmpKey) {
            case 'msgid':
                $entry['msgid'][] = self::convertString($str);
                $lastPreviousKey  = $tmpKey;

                break;
            case 'msgstr':
                $entry['msgstr'][] = self::convertString($str);

                $lastPreviousKey = $tmpKey;

                break;

            default:
                break;
        }

        return [$entry, $lastPreviousKey];
    }