public function __construct(Customweb_Payment_Authorization_IInvoiceItem $item = null)
 {
     if ($item !== null) {
         $this->sku = $item->getSku();
         $this->name = $item->getName();
         $this->taxRate = $item->getTaxRate();
         $this->amountIncludingTax = $item->getAmountIncludingTax();
         $this->quantity = $item->getQuantity();
         $this->type = $item->getType();
         $this->originalSku = $item->getOriginalSku();
         $this->requiresShipping = $item->isShippingRequired();
     }
 }