@Override
  public void cacheBlock(BlockCacheKey cacheKey, Cacheable buf) {
    cacheBlock(cacheKey, buf, false);
  }
Cache the block with the specified name and buffer.
@param cacheKey block's cache key
@param buf      block buffer
hbase-server/src/main/java/org/apache/hadoop/hbase/io/hfile/bucket/BucketCache.java