code: def maybe_download_mnist_file(file_name, datadir=None, force=False):
      warnings.warn(utils_mnist_warning)
      url = os.path.join(
          "https://storage.googleapis.com/cvdf-datasets/mnist/",
          file_name,
      )
      return dataset.maybe_download_file(url, datadir=None, force=False)
  
file_path: cleverhans/cleverhans_v3.1.0/cleverhans/utils_mnist.py
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  from __future__ import unicode_literals
  import os
  import tempfile
  import warnings
  from cleverhans import dataset
label_desc: Use image node_id 1 for calling a global function with example usage: maybe_download_mnist_file(file_name, datadir, force) and returns: dataset