class_docstr: Reads one single task in the bAbI tasks format as formulated in
  Towards AI-Complete Question Answering: A Set of Prerequisite Toy Tasks
  (https://arxiv.org/abs/1502.05698). Since this class handle a single file,
  if one wants to load multiple tasks together it has to merge them into a
  single file and use this reader.
  
  Registered as a `DatasetReader` with name "babi".
  
  # Parameters
  
  keep_sentences : `bool`, optional, (default = `False`)
      Whether to keep each sentence in the context or to concatenate them.
      Default is `False` that corresponds to concatenation.
  token_indexers : `Dict[str, TokenIndexer]`, optional (default=`{"tokens": SingleIdTokenIndexer()}`)
      We use this to define the input representation for the text.  See :class:`TokenIndexer`.
class_docstr_tok: ["Reads","one","single","task","in","the","bAbI","tasks","format","as","formulated","in","Towards","AI-Complete","Question","Answering",":","A","Set","of","Prerequisite","Toy","Tasks","(","https",":","\/\/arxiv.org\/abs\/1502.05698",")",".","Since","this","class","handle","a","single","file",",","if","one","wants","to","load","multiple","tasks","together","it","has","to","merge","them","into","a","single","file","and","use","this","reader",".","Registered","as","a","`","DatasetReader","`","with","name","``","babi","''",".","#","Parameters","keep_sentences",":","`","bool","`",",","optional",",","(","default","=","`","False","`",")","Whether","to","keep","each","sentence","in","the","context","or","to","concatenate","them",".","Default","is","`","False","`","that","corresponds","to","concatenation",".","token_indexers",":","`","Dict","[","str",",","TokenIndexer","]","`",",","optional","(","default=","`","{","``","tokens","''",":","SingleIdTokenIndexer","(",")","}","`",")","We","use","this","to","define","the","input","representation","for","the","text",".","See",":","class",":","`","TokenIndexer","`","."]
code: def apply_token_indexers(self, instance: Instance) -> None:
      if self._keep_sentences:
          for text_field in instance.fields["context"]:  # type: ignore
              text_field._token_indexers = self._token_indexers  # type: ignore
      else:
          instance.fields["context"]._token_indexers = self._token_indexers  # type: ignore
      instance.fields["question"]._token_indexers = self._token_indexers  # type: ignore
      instance.fields["answer"]._token_indexers = self._token_indexers
  
file_path: allennlp/allennlp/data/dataset_readers/babi.py
imports: import logging
  from typing import Dict, List
  from allennlp.common.file_utils import cached_path
  from allennlp.data.dataset_readers.dataset_reader import DatasetReader, PathOrStr
  from allennlp.data.instance import Instance
  from allennlp.data.fields import Field, TextField, ListField, IndexField
  from allennlp.data.token_indexers import TokenIndexer, SingleIdTokenIndexer
  from allennlp.data.tokenizers import Token
label_desc: Use image node_id 4 for calling the BabiReader obj's underlying member method code with example usage: obj.apply_token_indexers(instance) without return types