class Car {
   String madeby;
   static Map garage;

   factory Car(String manufacturer) {
      if(Car.garage == null) Car.garage=new Map();

      if (Car.garage.containsKey(manufacturer)!=null) return Car.garage[manufacturer];
      else {
         Car newcar = new Car.buy(manufacturer);
         Car.garage[manufacturer] = newcar;
         return newcar;
      }
   }

   Car.buy(this.madeby);
}

main() {
   var onecar = new Car("Ferrari");
   var anothercar = new Car("Ferrari");
}