@Override
      public void beforeProcessMessage(ClusterDistributionManager dm, DistributionMessage message) {
        if (message instanceof ReplyMessage && replyId != -0xBAD
            && replyId == message.getProcessorId() && !done && count.incrementAndGet() == 2) {
          task.run();
          done = true;
        }
      }
Test what happens when we restart persistent members while there is an accessor concurrently
performing puts.
geode-core/src/distributedTest/java/org/apache/geode/internal/cache/backup/BackupDistributedTest.java