function getNextLevels($deltaLevel)
    {
        $prevLevels = $this->getPrevLevels($deltaLevel);
        $return = $this->getLevels();
        foreach ($return as $key => $level) {
            if (in_array($level, $prevLevels) || $level == $deltaLevel) {
                unset($return[$key]);
            }
        }
        return array_values($return);
    }