src/Entities/Orders/OrderItem.php
public function jsonSerialize()
    {
        return [
            'id' => $this->getId(),
            'price' => $this->getPrice(),
            'markup' => $this->getMarkup(),
            'unitPrice' => $this->getUnitPrice(),
            'quantity' => $this->getQuantity(),
            'linePrice' => $this->getLinePrice(),
            'enabled' => $this->isEnabled(),
            'detail' => $this->getDetail(),
            'status' => $this->getStatus(),
            'note' => $this->getNote(),
            'itemDiscount' => $this->getItemDiscount(),
            'readyEstimate' => $this->getReadyEstimate(),
            'extras' => $this->getExtras(),
            'options' => $this->getOptions(),
            'instorePaymentRequired' => $this->isInstorePaymentRequired(),
        ];
    }
public function jsonSerialize()
    {
        return [
            'id' => $this->getId(),
            'price' => $this->getPrice(),
            'markup' => $this->getMarkup(),
            'unitPrice' => $this->getUnitPrice(),
            'quantity' => $this->getQuantity(),
            'linePrice' => $this->getLinePrice(),
            'enabled' => $this->isEnabled(),
            'detail' => $this->getDetail(),
            'status' => $this->getStatus(),
            'note' => $this->getNote(),
            'itemDiscount' => $this->getItemDiscount(),
            'readyEstimate' => $this->getReadyEstimate(),
            'extras' => $this->getExtras(),
            'options' => $this->getOptions(),
            'instorePaymentRequired' => $this->isInstorePaymentRequired(),
        ];
    }
Specify data which should be serialized to JSON