code: def _maybe_download():
      """Downloads the MNIST dataset if it is not there already."""
      data_url = "http://www.iro.umontreal.ca/~lisa/deep/data/mnist/mnist.pkl.gz"
      filename = data_url.split("/")[-1]
      filepath = os.path.join(_get_data_dir(), filename)
      if not os.path.exists(filepath):
  
          def _progress(count, block_size, total_size):
              print(
                  "\r>> Downloading %s %.1f%%"
                  % (
                      filename,
                      float(count * block_size)
                      / float(total_size)
                      * 100.0,
                  )
              )
  
          filepath, _ = urllib.urlretrieve(
              data_url, filepath, _progress
          )
          statinfo = os.stat(filepath)
          print(
              "Successfully downloaded %s %d bytes."
              % (filename, statinfo.st_size)
          )
      else:
          print("Data already present on disk.")
      return filepath
  
file_path: trax/trax/tf_numpy/examples/mnist/dataset.py
imports: import gzip
  import os
  import pickle
  import random
  import urllib
  import numpy
label_desc: Use image node_id 3 for calling a global function with example usage: _maybe_download() and returns: filepath