code: def _get_lsun(directory, category, split_name):
      """Downloads all lsun files to directory unless they are there."""
      generator_utils.maybe_download(
          directory,
          _LSUN_DATA_FILENAME % (category, split_name),
          _LSUN_URL % (category, split_name),
      )
  
file_path: tensor2tensor/tensor2tensor/data_generators/image_lsun.py
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import io
  import os
  import zipfile
  from tensor2tensor.data_generators import generator_utils
  from tensor2tensor.data_generators import image_utils
  from tensor2tensor.utils import registry
  import tensorflow.compat.v1
label_desc: Use image node_id 2 for calling a global function with example usage: _get_lsun(directory, category, split_name) without return types