#[test]
fn test_roundtrip_invariant() {
let data = vec![1u8, 2, 3, 4, 5];
let encoded: Vec<u8> = data.iter().map(|x| x.wrapping_add(1)).collect();
let decoded: Vec<u8> = encoded.iter().map(|x| x.wrapping_sub(1)).collect();
assert_eq!(data, decoded);
}
#[test]
fn test_associativity() {
let a: u64 = 100;
let b: u64 = 200;
let c: u64 = 300;
assert_eq!((a + b) + c, a + (b + c));
}