public function defaultLocale()
    {
        $locale = $this->getCore()->config('locale.translation-default');

        if ($locale) {
            return $locale;
        }

        // Fall back to default based on CMS configuration and app locale.
        $locale    = app()->getLocale();
        $available = $this->availableLocales();

        // If no translation locales are set, use app's locale as default.
        // If current app locale is available, use it as default.
        if ( ! count($available) || in_array($locale, $available)) {
            return $locale;
        }

        return head($available);
    }