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kotlinlang

Can I make generated Swift protocol properties covariant?

My case:

Kotlin:
```
interface Article {
    val id: Int
    val category: Category
}

interface Category {
    val id: Int
}
```

Swift:
```
@objc
class RealmArticle: Object, KNArticle {
    @objc dynamic var id: Int32 = 0
    @objc dynamic var category: RealmCategory = RealmCategory() // type does not conform to protocol KNArticle
}

@objc
class RealmCategory: Object, KNCategory {
    @objc dynamic var id: Int32 = 0
}
```

&gt;     @objc dynamic var category: RealmCategory = RealmCategory() // type does not conform to protocol KNArticle

This limitation is imposed by Swift, not Kotlin. How do you suggest to change generated `KNArticle` protocol to support covariant overriding in Swift?