That's the IntelliJ's magic (android studio is based on it), and that's also why Kotlin is feeling so great compared to other similar language that try to do th

That's the IntelliJ's magic (android studio is based on it), and that's also why Kotlin is feeling so great compared to other similar language that try to do the same(at least to me); being a jetbrain's made language it has perfect support by their tooling.