class_docstr: atis data class for nlu joint task.
code: def download(self) -> bool:
      train_url = (
          "https://github.com/howl-anderson/ATIS_dataset/raw/master/"
          "data/raw_data/ms-cntk-atis/atis.train.pkl"
      )
      test_url = (
          "https://github.com/howl-anderson/ATIS_dataset/raw/master/"
          "data/raw_data/ms-cntk-atis/atis.test.pkl"
      )
      try:
          wget.download(train_url, self.download_dir)
          wget.download(test_url, self.download_dir)
      except Exception as e:
          logging.warning(repr(e))
          return False
      return True
  
file_path: delta/delta/data/datasets/atis.py
imports: import os
  import traceback
  import wget
  from absl import logging
  from delta.data.datasets.base_dataset import BaseDataSet
  from delta.data.datasets.utils import summary_joint_nlu_data
  from delta.utils.register import registers
label_desc: Use image node_id 2 for calling the ATIS obj's underlying member method code with example usage: obj.download() and returns: True, False