class Dog(val feet: Array<Foot>) {
}

class Foot {
    fun move(): Unit = TODO()
}

fun main() {
    val feet = arrayOf(Foot(), Foot(), Foot(), Foot())
    val dog = Dog(feet)

    for(foot in dog.feet) {
        foot.move()
    }
}

// We're copying the reference of the array, so in theory, it can still
// be changed from outside, which is yet another code smell. A better
// approach would be to create a copy of the array inside the class
// instead of holding the reference.
class Dog(private val feet: Array<Foot>) {
    fun walk() {
        for(foot in feet) {
            foot.move()
        }
    }
}

class Foot {
    fun move(): Unit = TODO()
}

fun main() {
    val feet = arrayOf(Foot(), Foot(), Foot(), Foot())
    val dog = Dog(feet)
    dog.walk()
}