class_docstr: Abstract BPE Helper.
  
  BPE Helper subclasses must implement appropriate abstractmethods.
class_docstr_tok: ["Abstract","BPE","Helper",".","BPE","Helper","subclasses","must","implement","appropriate","abstractmethods","."]
docstr: Subclasses _should_ override __init__ to initialize other things.
docstr_tok: ["Subclasses","_should_","override","__init__","to","initialize","other","things","."]
code: def __init__(self, opt: Opt, shared: TShared = None):
      """
      Subclasses _should_ override __init__ to initialize other things.
      """
      from parlai.core.dict import DictionaryAgent
  
      self.lower = opt.get("dict_lower", DictionaryAgent.default_lower)
      self.maxtokens = opt.get(
          "dict_maxtokens", DictionaryAgent.default_maxtokens
      )
      self.minfreq = opt.get(
          "dict_minfreq", DictionaryAgent.default_minfreq
      )
  
      self.opt = opt
      self.debug = opt.get("bpe_debug", False)
      self.add_prefix_space = opt.get("bpe_add_prefix_space", False)
      self._special_tokens: Dict[str, int] = {}
      self.bpe_dropout: Optional[float] = opt.get("bpe_dropout")
      self._bpe_dropout_enabled = False
  
imports: from parlai.core.params import ParlaiParser
  from abc import ABC, abstractmethod
  from functools import lru_cache
  import json
  import os
  import random
  import re
  from typing import Dict, List, Optional, Set, Tuple
  from typing_extensions import final
  from parlai.core.build_data import download, make_dir
  from parlai.core.opt import Opt
  from parlai.utils.misc import warn_once
  from parlai.utils.typing import TShared
  from parlai.utils.io import PathManager
  import parlai.utils.logging
label_desc: Use image node_id 1 to create a new BPEHelper object from inherited base classes: ABC with example: obj = BPEHelper(opt, shared)