class_docstr: A single training/test example for simple sequence classification.
  
  For examples without an answer, the start and end position are -1.
code: def __repr__(self):
      s = ""
      s += "qas_id: %s" % (tokenization.printable_text(self.qas_id))
      s += ", question_text: %s" % (
          tokenization.printable_text(self.question_text)
      )
      s += ", doc_tokens: [%s]" % (" ".join(self.doc_tokens))
      if self.start_position:
          s += ", start_position: %d" % (self.start_position)
      if self.start_position:
          s += ", end_position: %d" % (self.end_position)
      if self.start_position:
          s += ", is_impossible: %r" % (self.is_impossible)
      return s
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import collections
  import json
  import math
  import os
  import random
  import mesh_tensorflow
  import mesh_tensorflow.bert.bert
  import mesh_tensorflow.bert.optimization
  import mesh_tensorflow.bert.tokenization
  import six
  from six.moves import range
  import tensorflow.compat.v1
  from tensorflow.compat.v1 import estimator
label_desc: Use image node_id 3 for calling the SquadExample obj's underlying member method code with example usage: obj.__repr__() and returns: s