Add support for serialize_nulls build config option

[twklessor]

Add support for serialize_nulls build config option. This option will enable that null fields are always serialized as null.

[knaeckeKami]

Thanks! I'll take a look at it soon.

[knaeckeKami]

So, to get on the same page:

You want a feature that always includes all null values when serialization, right?

Afaik this can be done in a much more simple way by just adding

@BuiltValueSerializer(serializeNulls: true)

as an annotation to the serializer, no custom serializer is needed for that. The Custom Serializer was needed to have the distinction between absent and null values.

[twklessor]

Yes that's right. I almost expected you to have an easier solution. To be honest I used the work you'd already done in the branch with the Value wrapper concept.

[twklessor]

Sorry to come back months later but what is the status of this?