public double calculateDeliveryCost(){
        
        //instance varibles
        double deliveryCost = 0;
        double aleCost=0;
        Ale ale;
        Iterator itr = products.iterator();
        ArrayList ales = new ArrayList();
        Product product;
        
        //go through order and check is product is an ale
        while (itr.hasNext()) {
            product = (Product) itr.next();
            //if product is an ale add to ales list
            if(product.getClass().toString().equals("class Ale")){
                ales.add(product);
                //test ales size to ensure ale added or cake not added
                System.out.println(ales.size());
            }
        }
        //this is where the problem is

        //if ale list is empty calculate cost as normal by adding 2 pound to each item
        if(ales.isEmpty()){
            while (itr.hasNext()) {
                product = (Product) itr.next();
                deliveryCost += product.getPrice() + 2;
            }
        } 
        //else is ales is not empty gp thourgh the ales list and calculate the total cost for ales
        else{
            Iterator itr2 = ales.iterator();
            while(itr2.hasNext()){
                ale = (Ale) itr2.next();
                aleCost += ale.getPrice();
            //if the cost is = or > than 50 then delivery = 0
            if(aleCost >= 50){
                deliveryCost = 0.00;
            }
        }
        }
        return(deliveryCost);
    }