code: @Override
    public BlockMeta getVolatileBlockMeta(long blockId) throws BlockDoesNotExistException {
      LOG.debug("getVolatileBlockMeta: blockId={}", blockId);
      try (LockResource r = new LockResource(mMetadataReadLock)) {
        return mMetaManager.getBlockMeta(blockId);
      }
    }
docs: TODO(bin): Make this method to return a snapshot.