class_docstr: Input data structure of BERT/ERNIE, can satisfy single sequence task like
  text classification, sequence lableing; Sequence pair task like dialog
  task.
  
  Args:
      guid: Unique id for the example.
      text_a: string. The untokenized text of the first sequence. For single
          sequence tasks, only this sequence must be specified.
      text_b: (Optional) string. The untokenized text of the second sequence.
          Only must be specified for sequence pair tasks.
      label: (Optional) string. The label of the example. This should be
          specified for train and dev examples, but not for test examples.
code: def __str__(self):
      if self.text_b is None:
          return "text={}\tlabel={}".format(self.text_a, self.label)
      else:
          return "text_a={}\ttext_b={},label={}".format(
              self.text_a, self.text_b, self.label
          )
  
imports: import os
  from paddlehub.utils.log import logger
label_desc: Use image node_id 2 for calling the InputExample obj's underlying member method code with example usage: obj.__str__() and returns: str, str