unused_change_addresses: vec![change(0), change(1)],
      change_addresses: vec![change(0), change(1)].into_iter().collect(),
      inputs: vec![outpoint(1), outpoint(2), outpoint(3)],
      outputs: vec![
        (recipient(), Amount::from_sat(5_000)),
        (change(0), Amount::from_sat(5_000)),
        (change(1), Amount::from_sat(1_724)),
      ],
      target: Target::Postage,
    };

    pretty_assert_eq!(
      tx_builder.build(),
      Ok(Transaction {
        version: 1,
        lock_time: LockTime::ZERO,
        input: vec![tx_in(outpoint(1)), tx_in(outpoint(2)), tx_in(outpoint(3))],
        output: vec![
          tx_out(5_000, recipient()),
          tx_out(5_000, change(0)),
          tx_out(1_724, change(1))
        ],
      })
    )
  }

  #[test]
  fn transactions_are_rbf() {
    let utxos = vec![(outpoint(1), Amount::from_sat(5_000))];

    assert!(TransactionBuilder::new(
      satpoint(1, 0),
      BTreeMap::new(),
      utxos.into_iter().collect(),
      BTreeSet::new(),
      recipient(),