class Item {
  n: Int
}

class Bag {
  items: multi Item
}

fn swap(mut a: Item, mut b: Item) -> Int {
  return 0
}

fn same_local(take it: Item) -> Int {
  return swap(it, it)
}

fn same_index(mut bag: Bag, i: Int) -> Int {
  return swap(bag.items[i], bag.items[i])
}