import java.utils.ArrayList

public class ShoppingCart {
  private ArrayList<Visitable> items;
  public double calculatePrice() {

    //create a visitor
    PostageVisitor visitor = new Cashier();
    
    //iterate through all items
    for(Visitable item: items) {
      item.accept(visitor);
    }

    double price = visitor.getTotalPrice();
    return price;
  }
}