public static String summaryTrace(
      final Transaction transaction, final long timer, final TransactionProcessingResult result) {
    final ObjectNode summaryLine = OBJECT_MAPPER.createObjectNode();
    summaryLine.put("output", result.getOutput().toUnprefixedHexString());
    summaryLine.put(
        "gasUsed",
        StandardJsonTracer.shortNumber(
            UInt256.valueOf(transaction.getGasLimit() - result.getGasRemaining())));
    summaryLine.put("time", timer);
    return summaryLine.toString();
  }
Used to produce debug traces of transactions
ethereum/api/src/main/java/org/hyperledger/besu/ethereum/api/jsonrpc/internal/processor/TransactionTracer.java