<@U1TCY49GT>: Another possibility would be to use...

# language-proposals

[juangamnik]

@dstarcev: Another possibility would be to use java.lang.reflect.Type or alike in the interface and for the Java version Class<T> is passed (which implicitly means nullable == true) and the Kotlin compiled code uses NullableClass<T> (a newly implemented class) which implements Type and delegates to an internal Class<T> and adds the information we need.