static async void AsyncMain()
{
var client = new UnleashedClient("", "");
var t1 = client.SalesInvoice.List();
var t2 = client.PaymentTerms.List();
Task.WaitAll(t1, t2);
var salesperson = (await client.SalesPersons.List()).FirstOrDefault();
var tax = (await client.Taxes.List()).First();
var salesorder = new SalesOrder();
salesorder.Customer = new LinkedCustomer("ACE001");
salesorder.CustomerRef = "PO00001";
salesorder.DeliveryCity = "DCITY";
salesorder.DeliveryCountry = "DCOUNTRY";
salesorder.DeliveryName = "DNAME";
salesorder.DeliveryPostCode = "DPOST";
salesorder.DeliveryRegion = "DREGION";
salesorder.DeliveryStreetAddress = "DSTREET";
salesorder.DeliverySuburb = "RSUBURB";
salesorder.OrderDate = new DateTime(2014, 4, 4);
salesorder.OrderStatus = "Placed";
salesorder.Tax = tax;
salesorder.SalesPerson = salesperson;
var item = new SalesOrderLine();
item.Guid = new Guid();
item.BCUnitPrice = 10.990m;
item.OrderQuantity = 1;
item.LineNumber = 1;
item.Product = new LinkedProduct("MTU001");
salesorder.SalesOrderLines.Add(item);
salesorder.CalcluateTotals();
await client.SalesOrders.Add(salesorder);
Console.ReadLine();
}