@Override
    protected void tryRegionServerReport(long reportStartTime, long reportEndTime)
      throws IOException {
      if (ARRIVE != null) {
        ARRIVE.countDown();
        ARRIVE = null;
        try {
          RESUME.await();
        } catch (InterruptedException e) {
        }
      }
      super.tryRegionServerReport(reportStartTime, reportEndTime);
    }
This UT is used to make sure that we will not accidentally change the way to generate online
servers. See HBASE-25774 and HBASE-25032 for more details.
hbase-server/src/test/java/org/apache/hadoop/hbase/replication/regionserver/TestRefreshPeerWhileRegionServerRestarts.java