AttributeError for from pyro.contrib.examples.util import MNIST

I am running the VAE tutorial, and got the following error messages due to the from pyro.contrib.examples.util import MNIST

import os

import numpy as np
import torch
from pyro.contrib.examples.util import MNIST

---------------------------------------------------------------------------
AttributeError                            Traceback (most recent call last)
~\AppData\Local\Temp/ipykernel_12404/1013685705.py in <module>
      3 import numpy as np
      4 import torch
----> 5 from pyro.contrib.examples.util import MNIST

~\AppData\Roaming\Python\Python37\site-packages\pyro\contrib\examples\util.py in <module>
     10 
     11 
---> 12 class MNIST(datasets.MNIST):
     13     mirrors = [
     14         "https://d2hg8soec8ck9v.cloudfront.net/datasets/mnist/"

~\AppData\Roaming\Python\Python37\site-packages\pyro\contrib\examples\util.py in MNIST()
     13     mirrors = [
     14         "https://d2hg8soec8ck9v.cloudfront.net/datasets/mnist/"
---> 15     ] + datasets.MNIST.mirrors
     16 
     17 

AttributeError: type object 'MNIST' has no attribute 'mirrors'

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