App\Modules\System\Controllers\Language::change PHP Method

    public function change($language)
    {
        $languages = Config::get('languages');
        // Only set language if it's in the Languages array
        if (preg_match('/[a-z]/', $language) && in_array($language, array_keys($languages))) {
            Session::set('language', $language);
            // Store the current Language in a Cookie lasting five years.
            Cookie::queue(PREFIX . 'language', $language, Cookie::FIVEYEARS);
        }
        return Redirect::back();
    }