@TestOnly
  public BloomFilter get(BloomFilterCacheKey key) throws IOException {
    LongConsumer emptyConsumer = l -> {};
    return get(key, false, emptyConsumer, emptyConsumer, emptyConsumer);
  }
This class is used to cache <code>BloomFilter</code> in IoTDB. The caching strategy is LRU.
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/storageengine/buffer/BloomFilterCache.java