I cannot find how to pass the reference of the objects so that I can let them point to a new location in the memory.
How to do this in Kotlin?

Code:

```
class Parent {

}

class Child : Parent {

}

class GlobalDataHolder {

    var globalChildVriable: Child? = null // imagine this is a static variable and can be accessed anywhere
}

class Activity() {
    var variable1 = Child()

    Helper.init(variable1, GlobalDataHolder.globalChildVriable) // inside onCreate()

}

class Helper {

    initStuff(variable1: Parent, globalVariable: Parent?) {
        if (globalVariable == null) {
             globalVariable = variable1 // error saying val cannot be re-assigned
        }
        else {
            variable1 = globalVariable!!
        }

    }
}

```

I want variable1 and globalVariable to be modifiable.
So the original owners of them will have the latest values.