class_docstr: Class to keep track of information on a sub-dataset of WMT.
code: def get_manual_dl_files(self, src):
      return self._inject_language(src, self._manual_dl_files)
  
imports: import codecs
  import functools
  import gzip
  import itertools
  import os
  import re
  from typing import List
  from xml.etree import ElementTree
  from absl import logging
  from etils import epath
  from tensorflow_datasets.core.utils import tree_utils
  import tensorflow_datasets.public_api
label_desc: Use image node_id 4 for calling the SubDataset obj's underlying member method code with example usage: obj.get_manual_dl_files(src) and returns: self