code: def __getitem__(self, index: int = 0) -> DataPair:
      if self.in_memory:
          return self.bi_sentences[index]
      else:
          return self._make_bi_sentence(
              self.source_lines[index], self.target_lines[index]
          )
  
imports: import logging
  import os
  from pathlib import Path
  from typing import List, Optional, Union
  import flair
  from flair.data import Corpus, DataPair, FlairDataset, Sentence, TextPair, _iter_dataset
  from flair.datasets.base import find_train_dev_test_files
  from flair.file_utils import cached_path, unpack_file, unzip_file
label_desc: Use image node_id 4 for calling the ParallelTextDataset obj's underlying member method code with example usage: obj.__getitem__(index) and returns: self, self