A question about Kryo and Window State

[Vishal Santoshi]

I have a running pipe with Window State in a class say

Class A{
     long a;
}

It uses the default KryoSerializer

I want to add a field to

Class A {
  long a;
  long b;
}

I need to suspend with SP and resume with the new version of Class A


Is there a definite way to do this. I tried

Class A {
  long a;
   @FieldSerializer.Optional("0")
  long b;
}

but that seems to default to 0 , even when the Aggregation is putting in
values.

Could somebody give pointers as to how to solve this

Thanks a ton.