@Override
    protected int getAckWaitThreshold() {
      // increasing ack wait threshold for this message as region/bucket initialization can take
      // time
      return super.getAckWaitThreshold() * 2;
    }
the message that triggers return from waitForAcceptance. This will be null if the target
member exited
geode-core/src/main/java/org/apache/geode/internal/cache/partitioned/ManageBackupBucketMessage.java