protected override void BuildSerializerContext(SerializerConfigurationContext configurationContext)
{
configurationContext.Entity <PoHeader>().HasArray(e => e.LineItems).WithElementName("lines").WithArrayItemName("line");
configurationContext.Entity <PoLine>().HasAttribute(e => e.Tax).WithName("tax");
configurationContext.Entity <PoLine>().HasAttribute(e => e.Quantity).WithName("qty");
}
