code: def _make_tar(self, root, *, name="archive.tar", remove=True):
      folder, files = self._make_folder(root, name=name.split(".")[0])
      archive = make_tar(root, name, folder, remove=remove)
      files = {
          str(archive / pathlib.Path(file).relative_to(root)): content
          for file, content in files.items()
      }
      return archive, files
  
imports: import gzip
  import pathlib
  import sys
  import numpy
  import pytest
  import torch
  from datasets_utils import make_fake_flo_file, make_tar
  from torchdata.datapipes.iter import FileOpener, TarArchiveLoader
  from torchvision.datasets._optical_flow import _read_flo
  from torchvision.datasets.utils import _decompress
  from torchvision.prototype.datasets.utils import Dataset, GDriveResource, HttpResource, OnlineResource
  from torchvision.prototype.datasets.utils._internal import fromfile, read_flo
label_desc: Use image node_id 3 for calling the TestOnlineResource obj's underlying member method code with example usage: obj._make_tar(root) and returns: archive,  files