code: public Map<String, Long> getTopKFromAsKeyString(Stat stat, int topK) {
        tryFlushAll();
        return topKeyWrapper.get(stat).topKAsString(topK);
     }
docs: Same as {@link #getTopKFrom(org.infinispan.stats.topK.StreamSummaryContainer.Stat, int)} but the keys are returned
  in their String format.