How to change "val" values in an object withotu changing the definition to "var"? I have a complex Kotlin data class, say something like this: data class Post( val message: Message, val dateAndTime: LocalTime, val postAuthor: Author?, val visitorsVisitedTimes: List ) and each of Message, LocalTime, ... are different data classes. I have an object of above Post data class. I want to parse it, access visitorsVisitedTimes field value, for each pair, replace Author object with corresponding postAuthor. I have to make similar changes in the Message object as...