public void notifyRangeProgress(
      final Step step, final Bytes32 startKeyHash, final Bytes32 endKeyHash) {
    checkNonEmpty(lastRangeIndex, "snapsync range collection");
    if (lastRangeIndex.containsKey(endKeyHash)) {
      final BigInteger lastPos = lastRangeIndex.get(endKeyHash);
      final BigInteger newPos = startKeyHash.toUnsignedBigInteger();
      percentageProgress.getAndAccumulate(
          BigDecimal.valueOf(100)
              .multiply(new BigDecimal(newPos.subtract(lastPos)))
              .divide(
                  new BigDecimal(RangeManager.MAX_RANGE.toUnsignedBigInteger()),
                  MathContext.DECIMAL32),
          BigDecimal::add);
      lastRangeIndex.put(endKeyHash, newPos);
      print(step);
    }
  }
Represents the number of trie nodes healed during the healing process.
ethereum/eth/src/main/java/org/hyperledger/besu/ethereum/eth/sync/snapsync/SnapSyncMetricsManager.java