public void updateQuality() {
        if (sellIn > 0) {
            quality++;
        }
        if(sellIn <= 10) {
            quality++;
        }
        if(sellIn <= 5) {
            quality++;
        }
        if (quality > 50) {
            quality = 50;
        }
        if (sellIn <= 0) {
            quality = 0;
        }
        sellIn--;
    }