code: CacheBucketOffset get(UUID keyHash, int generation) {
          CacheEntry entry;
          synchronized (this) {
              // First, check the tail cache.
              CacheBucketOffset tailOffset = this.tailOffsets.get(keyHash);
              if (tailOffset != null) {
                  return tailOffset;
              }
  
              entry = this.cacheEntries.get(getHashGroup(keyHash));
          }
  
          // Check the Cache Entry.
          if (entry != null) {
              Long r = entry.get(keyHash, generation);
              if (r != null) {
                  return CacheBucketOffset.decode(r);
              }
          }
  
          return null;
      }
docs: Looks up a cached offset for the given Key Hash.
  
  @param keyHash A UUID representing the Key Hash to look up.
  @return A {@link CacheBucketOffset} representing the sought result.