Self {
      blocks,
      change_addresses: Vec::new(),
      descriptors: Vec::new(),
      fail_lock_unspent,
      hashes,
      locked: BTreeSet::new(),
      mempool: Vec::new(),
      network,
      nonce: 0,
      sent: Vec::new(),
      transactions: BTreeMap::new(),
      utxos: BTreeMap::new(),
      version,
      wallets: BTreeSet::new(),
      loaded_wallets: BTreeSet::new(),
    }
  }

  pub(crate) fn push_block(&mut self, subsidy: u64) -> Block {
    let coinbase = Transaction {
      version: 0,
      lock_time: LockTime::ZERO,
      input: vec![TxIn {
        previous_output: OutPoint::null(),
        script_sig: script::Builder::new()
          .push_int(self.blocks.len().try_into().unwrap())
          .into_script(),
        sequence: Sequence::MAX,
        witness: Witness::new(),
      }],
      output: vec![TxOut {
        value: subsidy
          + self
            .mempool
            .iter()
            .map(|tx| {
              let fee = tx
                .input
                .iter()