False error: state sets declared two levels up the hierarchy are not kept across a call #505

// Grand.java
import liquidjava.specification.*;

@StateSet({"closed", "opened"})
@StateSet({"unlocked", "locked"})
class Grand {
    @StateRefinement(to = "closed(this) && unlocked(this)")
    public Grand() {}
}
// Parent.java
class Parent extends Grand {}
// Child.java
import liquidjava.specification.*;

public class Child extends Parent {
    @StateRefinement(from = "closed(this) && unlocked(this)", to = "opened(this)")
    public void open() {}

    @StateRefinement(from = "unlocked(this)")
    public void needsUnlocked() {}

    public static void main(String[] args) {
        Child c = new Child();
        c.open();
        c.needsUnlocked(); // lock set should be kept by open()
    }
}