docstr: Change format.
  
  Input: sent1: xxx sent2: yyy sent3: zzz
  Output: xxx. yyy. zzz.
docstr_tok: ["Change","format",".","Input",":","sent1",":","xxx","sent2",":","yyy","sent3",":","zzz","Output",":","xxx",".","yyy",".","zzz","."]
code: def _parse_context(self, cont: str) -> str:
      """
      Change format.
  
      Input: sent1: xxx sent2: yyy sent3: zzz
      Output: xxx. yyy. zzz.
      """
      parsed = re.split(r" ?sent\d+: ", cont)[1:]
      return ". ".join(parsed)
  
imports: import json
  import os
  import re
  from parlai.utils.data import DatatypeHelper
  from .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 tasks.reasoning.agents import StepByStepReasoningTeacher
  import random
label_desc: Use image node_id 4 for calling the EntailmentBankStepByStepReasoningTeacher obj's underlying member method code with example usage: obj._parse_context(cont) and returns: str