class_docstr: Transform the sentence containing answer with AlterSentence transformation.
  
  Example::
  
      origin sentence: Denver Broncos defeated the National Football
          Conference champion Carolina Panthers 24–10 to earn their
          third Super Bowl title.
      transformed sentence: Denver Broncos defeated the National Football
          Conference champ Carolina Panthers 24–10 to earn
          their 3rd Super Bowl rubric.
code: def __repr__(self):
      return "PerturbAnswer"
  
file_path: textflint/textflint/generation/transformation/MRC/perturb_answer.py
imports: import collections
  from ....common.settings import ORIGIN
  from ..transformation import Transformation
  from ....input.component.sample.mrc_sample import MRCSample
label_desc: Use image node_id 2 for calling the PerturbAnswer obj's underlying member method code with example usage: obj.__repr__() and returns: str