code: def load_dataset():
      """Download and reformat MNIST dataset"""
      mnist = tf.keras.datasets.mnist
      (x_train, y_train), (x_test, y_test) = mnist.load_data()
      x_train, x_test = x_train / 255.0, x_test / 255.0
      x_train = x_train[..., tf.newaxis]
      x_test = x_test[..., tf.newaxis]
      return (x_train, y_train), (x_test, y_test)
  
file_path: nni/examples/trials/mnist-tfv2/mnist.py
imports: import logging
  import tensorflow
  from tensorflow.keras import Model
  from tensorflow.keras.callbacks import Callback
  from tensorflow.keras.layers import Conv2D, Dense, Dropout, Flatten, MaxPool2D
  from tensorflow.keras.optimizers import Adam
  import nni
label_desc: Use image node_id 1 for calling a global function with example usage: load_dataset() and returns: x_train,  y_train,  x_test,  y_test