I also see a new warning "type mismatch: value of ...

# getting-started

[nkiesel]

I also see a new warning "type mismatch: value of a nullable type Optional<T> is used where non-nullable type is expected." for methods like fun <T> getEmpty(): Optional<T> = Optional.empty() . A similar looking function like fun <T> getList(): List<T> = emptyList() does not produce this warning. I guess it's because one is a Java and the other a Kotlin type, but I still don't see how to avoid the warning.