[Dart] Mixin

void main() {
  Animal animal = Animal();
  Bird().fly();  
  Fish().swim();
  Duck().move();  
  Duck().swim();
  Duck().fly();
}


mixin CanSwim {
  void swim() {
    print(‘change poisiton by swimming‘);
  }
}

mixin CanFly {
  void fly() {
    print(‘change poisiton by flying‘);
  }
}

class Animal {
  
  void move () {

    print(‘change position‘);
  }
}

class Fish extends Animal with CanSwim{
  
  @override
  void move () {
    super.move();
  }
}

class Bird extends Animal with CanFly{
  
  @override
  void move () {
    super.move();
  }
}

class Duck extends Animal with CanFly, CanSwim{
  
  @override
  void move () {
    super.move();
  }
}