code: def _add_missing_period(line):
      END_TOKENS = [
          ".",
          "!",
          "?",
          "...",
          "'",
          "`",
          '"',
          "\u2019",
          "\u2019",
          ")",
      ]
      if line.startswith("@highlight"):
          return line
      if line[-1] in END_TOKENS:
          return line
      return line + "."
  
imports: import re
  import html
  import logging
  import pandas
  import os
  import random
  import torch
  from pathlib import Path
  import pickle
  import shutil
  from collections import deque, namedtuple
  from torch.utils.data import Dataset, DataLoader, SequentialSampler
  from tokenizers import BertWordPieceTokenizer
  from transformers import BertTokenizer
label_desc: Use image node_id 2 for calling a global function with example usage: _add_missing_period(line) and returns: unknown, line, line