XData Swagger support does not reflect nullable fields

I have a service defined in XData where the input is a class that has Aurelius Nullable wrapped fields. I was hoping that the swagger support would identify been nullable and required fields.

e.g.
type
TInput = class
private
FOptional : Nullable;
FRequired : integer;
public
property Optional : Nullable read FOptional write FOptional;
property Required : integer read FRequired write FRequired;
end;

// ....
IMyService = interface(IInvokable)
[HttpPost]
function DoSomething(const AInput : TInput) : string;
end;