tensorflow_script_mode_horovod.ipynb failed CI

Link to the notebook:
https://github.com/aws/amazon-sagemaker-examples/blob/master/sagemaker-python-sdk/tensorflow_script_mode_horovod/tensorflow_script_mode_horovod.ipynb

Error:

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Exception encountered at "In [2]":
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ModuleNotFoundError Traceback (most recent call last)
in
4 import numpy as np
5
----> 6 import keras
7 from keras.datasets import mnist
8 (x_train, y_train), (x_test, y_test) = mnist.load_data()

ModuleNotFoundError: No module named 'keras'

Open sagemaker-python-sdk/tensorflow_script_mode_horovod/tensorflow_script_mode_horovod.ipynb and start at In [2], where the import keras failure occurs. Run the notebook or its CI validation to confirm the missing module, and consider the issue done when the notebook completes without ModuleNotFoundError and CI passes.

Written by the indexing model from the issue text.