class ShopifyAPI::DraftOrder

def complete(options = {})
  load_attributes_from_response(put(:complete, options, nil))
end

def send_invoice(draft_order_invoice = ShopifyAPI::DraftOrderInvoice.new)
  resource = post(:send_invoice, {}, draft_order_invoice.encode)
  ShopifyAPI::DraftOrderInvoice.new(ShopifyAPI::DraftOrder.format.decode(resource.body))
end