fn test_add() {
let b1 = BigInt::new(1 << 32);
let b2 = BigInt::from_vec(vec![0, 1]);
assert_eq!(&b1 + &b2, BigInt::from_vec(vec![1 << 32, 1]));
fn test_add() {
let b1 = BigInt::new(1 << 32);
let b2 = BigInt::from_vec(vec![0, 1]);
assert_eq!(&b1 + &b2, BigInt::from_vec(vec![1 << 32, 1]));