public Flyweight getFlyweight(String key){
        if(flyweightPool.containsKey(key)){
            return flyweightPool.get(key);
        }
        else{
            Flyweight flyweight;
            if("add".equals(key)){
                flyweight = new FlyweightAdder();
            }
            else{
                flyweight= new FlyweightMultiplier();
            }
            flyweightPool.put(key, flyweight);
            return flyweight;
                    }
    }