docs: public void remoteAck(final long seq) {
  
          //In replicated only master will be doing this.
          m_es.execute(new Runnable() {
              @Override
              public void run() {
                  try {
                      // ENG-12282: A race condition between export data source
                      // master promotion and getting acks from the previous
                      // failed master can occur. The failed master could have
                      // sent out an ack with Long.MIN and fails immediately after
                      // that, which causes a new master to be elected. The
                      // election and the receiving of this ack message happens on
                      // two different threads on the new master. If it's promoted
                      // while processing the ack, the ack may call `m_onDrain`
                      // while the other thread is polling buffers, which may
                      // never get discarded.
                      //
                      // Now that we are on the same thread, check to see if we
                      // are already promoted to be the master. If so, ignore the
                      // ack.
                      if (!m_es.isShutdown() && !m_mastershipAccepted.get()) {
                          setCommittedSeqNo(seq);
                          ackImpl(seq);
                      }
                  } catch (Exception e) {
                      exportLog.error("Error acking export buffer", e);
                  } catch (Error e) {
                      VoltDB.crashLocalVoltDB("Error acking export buffer", true, e);
                  }
              }
          });
      }