protected override void DeserializeMembers(ReadOnlySpan <byte> source, Order instance) { instance.Id = Fmt.DeserializeStructDefault <int>(source); instance.CustomerId = Fmt.DeserializeStructDefault <int>(source); // we ignore itemnsIsNull here as our class does not allow a null LineItems property Fmt.DeserializeObjects <LineItem>(source, (item) => instance.LineItems.Add(item), out bool itemsIsNull); }