Until Java fixes its type system to add nullable types (and not in that ridiculous tri-state nullability method that one JEP proposes), Kotlin will be several steps ahead of Java.

I can speak from experience that Fable 5.1 still writes code that compiles and usually runs fine but throws null pointer exceptions in reasonable edge cases.

Waiting so long for type safety and hoping it won't be a weird implementation.

Kotlin's implementation is very good, hoping with all my heart java will copy it