@Override
  public void addCacheListener(CacheListener listener) {
    // nothing
  }
This method prepares the batch of events and updates the thread-context with corresponding
counters, so that when remove is called by this thread, these events are destroyed from the
queue.This method should always be invoked within the {@code rwLock}.

@param batchSize - number of events to be peeked
@return - list of events peeked
geode-core/src/main/java/org/apache/geode/internal/cache/ha/HARegionQueue.java