class_docstr: A single training/test example for the Squad dataset, as loaded from disk.
  
  Attributes
  ----------
  qas_id
      The example's unique identifier
  query_text
      The query string
  context_text
      The context string
  answer_text
      The answer string
  start_position
      The character position of the start of the answer
  end_position
      The character position of the end of the answer
  title
      The title of the example
  answers
      None by default, this is used during evaluation.
      Holds answers as well as their start positions.
  is_impossible
      False by default, set to True if the example has no possible answer.
class_docstr_tok: ["A","single","training\/test","example","for","the","Squad","dataset",",","as","loaded","from","disk",".","Attributes","--","--","--","--","--","qas_id","The","example","'s","unique","identifier","query_text","The","query","string","context_text","The","context","string","answer_text","The","answer","string","start_position","The","character","position","of","the","start","of","the","answer","end_position","The","character","position","of","the","end","of","the","answer","title","The","title","of","the","example","answers","None","by","default",",","this","is","used","during","evaluation",".","Holds","answers","as","well","as","their","start","positions",".","is_impossible","False","by","default",",","set","to","True","if","the","example","has","no","possible","answer","."]
code: def to_json(self):
      return json.dumps(dataclasses.asdict(self), ensure_ascii=False)
  
imports: from typing import Optional, List, Tuple
  from collections import namedtuple
  import dataclasses
  from dataclasses import dataclass
  import re
  import numpy
  import warnings
  import os
  from tqdm.auto import tqdm
  import json
  import string
  from gluonnlp.data.tokenizers import BaseTokenizerWithVocab
  from gluonnlp.utils.preprocessing import match_tokens_with_char_spans
  from mxnet.gluon.utils import download
  import mxnet
label_desc: Use image node_id 1 for calling the SquadExample obj's underlying member method code with example usage: obj.to_json() and returns: json