public static function createKey(?string $msgid, ?string $msgctxt = null, ?string $msgid_plural = null): string
    {
        $key = '';
        if (!empty($msgctxt)) {
            $key .= $msgctxt . '|';
        }
        $key .= (string) $msgid;
        if (!empty($msgid_plural)) {
            $key .= '|' . $msgid_plural;
        }
        return $key;
    }