code: Map<UUID, CacheBucketOffset> getTailHashes(long segmentId) {
          return forSegmentCache(segmentId, SegmentKeyCache::getTailBucketOffsets, Collections.emptyMap());
      }
docs: Gets the unindexed Key Hashes, mapped to their latest offsets.
  
  @param segmentId The Id of the Segment to get Hashes for.
  @return The result.