code: def get_data():
      ds = ConcatData([dataset.Mnist("train"), dataset.Mnist("test")])
      ds = BatchData(ds, BATCH)
      ds = MapData(ds, lambda dp: [dp[0]])  # only use the image
      return ds
  
imports: import argparse
  import numpy
  import os
  import cv2
  import tensorflow
  from tensorpack import *
  from tensorpack.dataflow import dataset
  from tensorpack.tfutils import gradproc, optimizer, summary
  from tensorpack.tfutils.scope_utils import auto_reuse_variable_scope, under_name_scope
  from tensorpack.utils import viz
  from GAN import GANModelDesc, GANTrainer
label_desc: Use image node_id 5 for calling a global function with example usage: get_data() and returns: ds