Nestable\Services\NestableService::addAttr PHP Метод

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