And it's not an easy fix, because they're all defi...

# serialization

[Toddobryan]

And it's not an easy fix, because they're all defined in the JsonPrimitive class, which doesn't have access to isString. I'm happy to provide a pull request, but there's more than one way to do this and I don't want to spend time and then discover I've picked a way the maintainers don't like.