Is map.copyFrom staying?

It's vital to a lot of map-based games, but a note in the documentation says that "Such undocumented fields and methods may break in the future". Is copyFrom remaining or is it just an experimental feature?

That's one only @gilles can answer. But worst case you could always extend the map object with a custom script by the same name.
If I'm not completely mistaken 😃

Oh yeah, thank you :D