title: How do I easily restore purchases using the Amazon API?
body: <p>I'm trying to restore purchases just like iOS, and I can't figure out how to easily restore an IAP entitlement purchase with the Amazon API.</p>
  
  <p>If I send another request with the SKU to the <code>PurchasingManager</code>, it returns a <code>PurchaseResponse</code>, but that <code>PurchaseResponse</code> doesn't return a valid Receipt if the SKU has already been purchased. It's null.</p>
  
  <p>Seems like I would need that SKU to do any kind of processing.</p>