GR Specs

• product is ordinary SellIn = -1 quality 2 => quality = 0, sell_in = -2
• product is ordinary SellIn = 0 quality 2 => quality = 0
• product is ordinary SellIn > 0 quality 2, sell_in: 2, quality: 2 => quality: 1
• product is ordinary SellIn > 0 quality 0, sell_in: 2, quality: 0 => quality: 0
• product is Aged Brie quality is 50; quality: 50 => quality: 50
• product is Aged Brie SellIn > 0; Quality < 50; SellIn = 10; Quality = 40 => Quality = 41
• product is Sulfura SellIn > 0; Quality > 0; SellIn = 10; Quality = 30 => Quality = 30; SellIn = 10
• product is Backstage Pass with SellIn > 10; Quality > 0; SellIn = 15; Quality = 10 => Quality = 9
• product is Backstage Pass with SellIn <= 10; Quality > 0; SellIn = 10; Quality = 9 => Quality = 11
• product is Backstage Pass with SellIn <= 5 ; Quality > 0; SellIn = 4; Quality = 9 => Quality = 13
• product is Backstage Pass with SellIn = 0 ; Quality > 0; SellIn = 0; Quality = 9 => Quality = 13