public function onIsVisibleElement(Model $element, $isVisible): bool
    {
        $isVisible = (bool) $isVisible;

        // load module if it is a module include element
        if ($element instanceof ContentModel && $element->type == 'module') {
            $element = ModuleModel::findByPK($element->module);
        }

        if (!$element instanceof ModuleModel) {
            return $isVisible;
        }

        // do not limit for navigation module. so every module can access it
        $this->navClass = $element->bs_nav_class;

        return $isVisible;
    }