code: private boolean isBlockFinalizedWithLock(int namespaceId, Block b) {
      lock.readLock().lock();
      try {
        return isBlockFinalizedInternal(namespaceId, b, true);
      } finally {
        lock.readLock().unlock();
      }
    }
docs: is this block finalized? Returns true if the block is already
  finalized, otherwise returns false.