Override change type

Support
1

Hi all,
I’m learning Kotlin and I have a doubt. Suppose we have this JAVA classes:

public interface I {
    Observable<Integer> getValue();
}

public class C implements I {
    private BehaviorSubject<Integer> value;
    
    C(int value){
        this.value = BehaviorSubject.createDefault(value);
    }

    @Override
    public Observable<Integer> getValue() {
        return null;
    }
}

I try to do the same with Kotlin, doing this:

interface I {
    val value: Observable<Int>
}

class C(value: Int) : I {
    override val value: BehaviorSubject<Int> = BehaviorSubject.createDefault(value)
}

But is not the same.
The problem is when I construct an instance c of C, c.value give me a BehaviorSubject and not and Observable.
I don’t want that the client code sees that value is a BehaviorSubject. This is my internal representation!
How can I obtain the EXACTLY same java code in Kotlin?
Thanks in advance!

Edit: I can’t declare value in c as Observable, because internally I need a BehaviorSubject

2

Something like this maybe?

interface I {
	val value: Observable<Int>
}

class C(value: Int) : I {
	private val _value = BehaviorSubject.createDefault(value)
	
	override val value: Observable<Int> get() = _value
}
3

Oh right!
Thanks!