class_docstr: Paraphrase problem.
code: def _maybe_download(self, tmp_dir, dataset_split):
      filename = os.path.basename(_MS_COCO_ZIPPED_FILE)
      download_url = os.path.join(_MS_COCO_DOWNLOAD_URL, filename)
      path = generator_utils.maybe_download(
          tmp_dir, filename, download_url
      )
      unzip_dir = os.path.join(tmp_dir, filename.strip(".zip"))
      if not tf.gfile.Exists(unzip_dir):
          tf.logging.info("Unzipping data to {}".format(unzip_dir))
          zipfile.ZipFile(path, "r").extractall(unzip_dir)
  
      if dataset_split == problem.DatasetSplit.TRAIN:
          ms_coco_file = _MS_COCO_TRAIN_FILE
      else:
          ms_coco_file = _MS_COCO_DEV_FILE
      ms_coco_path = os.path.join(
          unzip_dir, "annotations", ms_coco_file
      )
      return ms_coco_path
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import collections
  import io
  import json
  import os
  import zipfile
  from tensor2tensor.data_generators import generator_utils
  from tensor2tensor.data_generators import problem
  from tensor2tensor.data_generators import text_problems
  from tensor2tensor.utils import registry
  import tensorflow.compat.v1
label_desc: Use image node_id 5 for calling the ParaphraseGenerationMsCocoProblem obj's underlying member method code with example usage: obj._maybe_download(tmp_dir, dataset_split) and returns: ms_coco_path