open class Vehicle {
    fun test() {
        println("test: ${this::class}")
    }
}

class Car: Vehicle()

class Truck: Vehicle()

val list = mutableListOf<Vehicle>()
val vehicle = Vehicle()
val car = Car()
val truck = Truck()

list.add(vehicle)
list.add(car)
list.add(truck)

for (curVehicle in list) {
    curVehicle.test()
}