controls.mapValues {
    val ans = EnumSet.noneOf(NotificationTarget::class.java)
    if (it.value.pushSwitch.isChecked) ans += NotificationTarget.PUSH
    if (it.value.emailSwitch.isChecked) ans += NotificationTarget.EMAIL
    ans
}

controls.mapValues {
    EnumSet.copyOf(
            listOf(
                    it.value.pushSwitch to NotificationTarget.PUSH,
                    it.value.emailSwitch to NotificationTarget.EMAIL
            )
                    .filter { it.first.isChecked }
                    .map { it.second }
    )
}