public function toArray()
    {
        return [
            'title' => $this->title,
            'description' => $this->description,
            'commission' => $this->commission,
            'costCentre' => $this->costCentre,
            'currencyCode' => $this->currencyCode,
            'netShippingCosts' => $this->netShippingCosts,
            'internalNote' => $this->getInternalNote(),
            'responsibleContact' => $this->createDataArray($this->responsibleContact),
            'items' => $this->itemsToArray(),
        ];
    }