class_docstr: atis2 data class for nlu joint task.
code: def download(self) -> bool:
      github_url = "https://github.com/yvchen/JointSLU.git"
      res = os.system(f"cd {self.download_dir}; git clone {github_url}")
      if res != 0:
          return False
      return True
  
file_path: delta/delta/data/datasets/atis2.py
imports: import os
  from absl import logging
  import shutil
  import traceback
  from delta.data.datasets.base_dataset import BaseDataSet
  from delta.utils.register import registers
label_desc: Use image node_id 3 for calling the ATIS2 obj's underlying member method code with example usage: obj.download() and returns: True, False