code: def download(self):
      if not osp.exists(self.dir):
          if decide_download(self.url):
              path = download_url(self.url, self.root)
              extract_zip(path, self.root)
              os.unlink(path)
          else:
              print("Stop download.")
              exit(-1)
  
imports: from typing import Optional, Union, Dict
  import os
  import shutil
  import os.path
  import torch
  import numpy
  from ogb.utils.url import decide_download, download_url, extract_zip, makedirs
  from ogb.lsc.utils import split_test
label_desc: Use image node_id 2 for calling the MAG240MDataset obj's underlying member method code with example usage: obj.download() without return types