我正在使用Laravel v6编写资源和资源集合。我希望使用资源集合内部资源的一些数据。例如，我有以下UserResource和UserCollection：

class UserResource extends JsonResource
{
    public $data = 0;
    /**
     * Transform the resource into an array.
     *
     * @param  \Illuminate\Http\Request  $request
     * @return array
     */
    public function toArray($request)
    {
        $this->data + = 5; 
        return [
            'id' => $this->id,
            'name' => $this->name,
            'email' => $this->email,
            'created_at' => $this->created_at,
            'updated_at' => $this->updated_at,
        ];
    }
    public function getAdditionalData(){
            return $this->data;
    }
}

class UserCollection extends ResourceCollection
{
    /**
     * Transform the resource collection into an array.
     *
     * @param  \Illuminate\Http\Request  $request
     * @return array
     */
    public function toArray($request)
    {
        return [
            'data' => $this->collection,
            'additional-data' => [
                (new UserResource(null))->getAdditionalData(),
            ],
        ];
    }
}

我想返回一些在资源中计算的数据，并在资源集合中使用它。我收到的值是0，而我期望的是5。我如何将这些数据从资源返回到集合中？