Nestable\Services\NestableService::parent PHP Method

    public function parent($parent = false)
    {
        if ($parent) {
            $this->parents = !is_array($parent) ? [$parent] : $parent;
            if (func_num_args() > 1) {
                $this->parents = func_get_args();
            }
        }
        return $this;
    }