import org.checkerframework.checker.initialization.qual.UnknownInitialization;
import org.checkerframework.checker.nullness.qual.*;
import org.checkerframework.checker.nullness.qual.RequiresNonNull;

public class Uninit9 {
    public Object f;

    Uninit9() {
        f = new Object();
    }
}

class Uninit9Sub extends Uninit9 {
    Uninit9Sub() {
        super();
        fIsSetOnEntry();
    }

    @RequiresNonNull("f")
    void fIsSetOnEntry(@UnknownInitialization Uninit9Sub this) {}
}