{
        for (id, balance) in unallocated {
          if balance > 0 {
            *allocated[vout].entry(id).or_default() += balance;
          }
        }
      }
    }

    // update outpoint balances
    let mut buffer: Vec<u8> = Vec::new();
    for (vout, balances) in allocated.into_iter().enumerate() {
      if balances.is_empty() {
        continue;
      }

      // increment burned balances
      if tx.output[vout].script_pubkey.is_op_return() {
        for (id, balance) in &balances {
          *burned.entry(*id).or_default() += balance;
        }
        continue;
      }

      buffer.clear();

      let mut balances = balances.into_iter().collect::<Vec<(u128, u128)>>();

      // Sort balances by id so tests can assert balances in a fixed order
      balances.sort();

      for (id, balance) in balances {
        varint::encode_to_vec(id, &mut buffer);
        varint::encode_to_vec(balance, &mut buffer);
      }

      self.outpoint_to_balances.insert(
        &OutPoint {
          txid,
          vout: vout.try_into().unwrap(),