<Why is my kotlin hash set not adding elements> I ...

# stackoverflow

[user]

Why is my kotlin hash set not adding elements
I am new to kotlin and I want to make an abstract/open class or interface, something that can be implemented by other classes. Let's call it Test. Now Test needs to have a HashSet (the docs say it requires less memory than a normal set) that every derived class will implement and fill with its own values.
interface Test {
val players: HashSet
}
class Supa: Test {
override val players = hashSetOf()
fun later() {
players.add("new player")
}
}
fun main() {...