docs: void prepareTransferMastership(int newLeaderHostId) {
          if (!m_mastershipAccepted.get()) {
              return;
          }
          m_es.submit(new Runnable() {
              @Override
              public void run() {
                  // memorize end sequence number of the most recently pushed buffer from EE
                  // but if we already wait to switch mastership, don't update the drain-to
                  // sequence number to a greater number
                  m_seqNoToDrain = Math.min(m_seqNoToDrain, m_lastPushedSeqNo);
                  m_newLeaderHostId = newLeaderHostId;
                  // if no new buffer to be drained, send the migrate event right away
                  mastershipCheckpoint(m_lastReleasedSeqNo);
              }
          });
      }