protected function can_add_more_courses_to_category($category) {
        global $CFG;
        $limit = 20;
        if (!empty($CFG->navcourselimit)) {
            $limit = (int)$CFG->navcourselimit;
        }
        if (is_numeric($category)) {
            if (!array_key_exists($category, $this->addedcategories)) {
                return true;
            }
            $coursecount = count($this->addedcategories[$category]->children->type(self::TYPE_COURSE));
        } else if ($category instanceof navigation_node) {
            if (($category->type != self::TYPE_CATEGORY) || ($category->type != self::TYPE_MY_CATEGORY)) {
                return false;
            }
            $coursecount = count($category->children->type(self::TYPE_COURSE));
        } else if (is_object($category) && property_exists($category,'id')) {
            $coursecount = count($this->addedcategories[$category->id]->children->type(self::TYPE_COURSE));
        }
        return ($coursecount <= $limit);
    }