hierarchicalizeWithIds (x:rest) = do
  rest' <- hierarchicalizeWithIds rest
  return $ (Blk x) : rest'
hierarchicalizeWithIds (x:rest) = do
  rest' <- hierarchicalizeWithIds rest
  return $ (Blk x) : rest'
hierarchicalizeWithIds (x:rest) = do
  rest' <- hierarchicalizeWithIds rest
  return $ (Blk x) : rest'