I put things like that in a separate namespace. If my namespace is Foobar I'll have a Foobar.Impl namespace. One of the lessons I've learned is that very littl

I put things like that in a separate namespace. If my namespace is Foobar I'll have a Foobar.Impl namespace. One of the lessons I've learned is that very little needs to be private, and there's a lot of advantage of not having things private. Putting that in a clearly defined namespace allows access when needed, for testing or workarounds, while conveying the needed "if you use this you're on your own".