public function l10nIdent($lang = null)
    {
        if ($this->ident === '') {
            throw new RuntimeException('Missing Property Identifier');
        }

        if (!$this->l10n()) {
            throw new LogicException(sprintf(
                'Property "%s" is not multilingual',
                $this->ident
            ));
        }

        if ($lang === null) {
            $lang = $this->translator()->getLocale();
        } elseif (!is_string($lang)) {
            throw new InvalidArgumentException(sprintf(
                'Language must be a string for Property "%s"',
                $this->ident
            ));
        }

        return sprintf('%1$s_%2$s', $this->ident, $lang);
    }