Nestable\Services\NestableService::ulAttr PHP Method

    public function ulAttr($attr, $value = '')
    {
        if (func_num_args() > 1) {
            $this->optionUlAttr[$attr] = $value;
        } elseif (is_array($attr)) {
            $this->optionUlAttr = $attr;
        }
        return $this;
    }