mapdev\FacebookMessenger\Components\ReceiptElement::toArray PHP Метод

    public function toArray()
    {
        $result = ['title' => $this->title, 'price' => $this->price];
        if (!is_null($this->subtitle)) {
            $result['subtitle'] = $this->subtitle;
        }
        if (!is_null($this->quantity)) {
            $result['quantity'] = $this->quantity;
        }
        if (!is_null($this->currency)) {
            $result['currency'] = $this->currency;
        }
        if (!is_null($this->image_url)) {
            $result['image_url'] = $this->image_url;
        }
        return $result;
    }