code: def clean_answer(self, answer):
      while answer.rfind("}") < answer.rfind("{"):
          answer = answer[: answer.rfind("}")]
      return answer
  
imports: import glob
  import json
  import os
  import random
  import re
  from parlai.tasks.math_dataset.build import build
  from parlai.core.opt import Opt
  from parlai.core.params import ParlaiParser
  from parlai.utils.io import PathManager
  from typing import List, Optional
  from parlai.tasks.reasoning.agents import MWPStepsReasoningTeacher
label_desc: Use image node_id 9 for calling the MathDatasetStepByStepReasoningTeacher obj's underlying member method code with example usage: obj.clean_answer(answer) and returns: answer