Zenderable

void main() {
  Car nissan = Car();
  ElectricCar opel = ElectricCar();
  FlyingCar vw = FlyingCar();
  print(nissan.numberOfSeats);
  nissan.drive();
  print(opel.numberOfSeats);
  opel.drive();
  vw.drive();
  

Zenderable

void main() {
  Human mark = Human(186);
  Human elon = Human(169);
  print(mark.height);
  print(elon.height);
}

class Human {
  int height;
  Human(int height) {