code: def download_model(model_name, dst_dir="./", meta_info=None):
      if meta_info is None:
          meta_info = _default_model_info
      meta_info = dict(meta_info)
      if model_name not in meta_info:
          return (None, 0)
      if not os.path.isdir(dst_dir):
          os.mkdir(dst_dir)
      meta = dict(meta_info[model_name])
      assert "symbol" in meta, "missing symbol url"
      model_name = os.path.join(dst_dir, model_name)
      download_file(meta["symbol"], model_name + "-symbol.json")
      assert "params" in meta, "mssing parameter file url"
      download_file(meta["params"], model_name + "-0000.params")
      return (model_name, 0)
  
label_desc: Use image node_id 1 for calling a global function with example usage: download_model(model_name, dst_dir, meta_info) and returns: model_name,  int, None,  int