Option 1: Explicit inclusion only
private SomeType type;
@IndexPath allows for further extension, but I could live with simple
strings as well.
I would be ecstatic if just @IndexPaths was added in the near future.
It would be cleanly separated from @IndexEmbedded and potential for
confusion around depth. Then if the community desires it, or makes some
noise about the lack of the prune/exclude option, that can be added
later with no impact to the @IndexPaths approach.