code: def get_data():
      train = BatchData(dataset.Mnist("train"), 128)
      test = BatchData(dataset.Mnist("test"), 256, remainder=True)
      return train, test
  
file_path: tensorpack/examples/keras/mnist-keras.py
imports: import tensorflow
  from tensorflow import keras
  from contextlib import contextmanager
  from tensorpack import *
  from tensorpack.contrib.keras import KerasPhaseCallback
  from tensorpack.dataflow import dataset
  from tensorpack.utils.argtools import memoized
  from tensorpack.utils.gpu import get_num_gpu
  from tensorpack.tfutils.tower import get_current_tower_context
label_desc: Use image node_id 3 for calling a global function with example usage: get_data() and returns: train,  test