var PostPackages = InventoryList<PostPackage>(items: [])
PostPackages.add(item: PostPackage())
print("Number of posts elements: \(PostPackages.numberOfItems())")

var FoodPackages = InventoryList<FoodPackage>(items: [])
FoodPackages.add(item: FoodPackage())
print("Is capacity low? \(FoodPackages.isCapacityLow())")
FoodPackages.remove()
print("Number of food elements: \(FoodPackages.numberOfItems())")