public boolean isEmptyAckList() {
    synchronized (threadIdToSeqId.list) {
      return threadIdToSeqId.list.isEmpty();
    }
  }
Creates a HARegionQueue object with default attributes. used by tests

@return an instance of HARegionQueue
@since GemFire 5.7
geode-core/src/main/java/org/apache/geode/internal/cache/ha/HARegionQueue.java