docs: void addToRepairLog(Iv2RepairLogResponseMessage msg)
      {
          // don't add the null payload from the first message ack to the repair log
          if (msg.getPayload() == null) {
              return;
          }
          // MP repair log has at most two messages, complete message for prior transaction
          // and fragment message for current transaction, don't add message before prior completion
          if (msg.getTxnId() <= m_maxSeenCompleteTxnId) {
              return;
          }
          Iv2RepairLogResponseMessage prev = m_repairLogUnion.floor(msg);
          if (prev != null && (prev.getTxnId() != msg.getTxnId())) {
              prev = null;
          }
  
          if (msg.getPayload() instanceof CompleteTransactionMessage) {
              // prefer complete messages to fragment tasks. Completion message also erases prior staled messages
              m_repairLogUnion.removeIf((p) -> p.getTxnId() <= msg.getTxnId());
              m_repairLogUnion.add(msg);
              m_maxSeenCompleteTxnId = msg.getTxnId();
          }
          else if (prev == null) {
             m_repairLogUnion.add(msg);
          }
      }