// My: to be implemented
// DISABLE-ERRORS
expect sealed class My(x: Double) {
    abstract val num: Int
    open fun isGood(): Boolean

    object First : My {
        override val num: Int
    }

    class Some(num: Int) : My {
        override val num: Int
    }

    object Best : My {
        override val num: Int
        override fun isGood(): Boolean

    }

    val x: Double

}