docstr: Lower text and remove punctuation, articles and extra whitespace 
docstr_tok: ["Lower","text","and","remove","punctuation",",","articles","and","extra","whitespace"]
code: def normalize_answer(s: str):
      """Lower text and remove punctuation, articles and extra whitespace"""
  
      return QAMetrics.white_space_fix(
          QAMetrics.remove_articles(QAMetrics.remove_punc(s.lower()))
      )
  
imports: import collections
  import json
  import re
  import string
  import torch
  from tqdm import tqdm
  from nemo.collections.nlp.parts.utils_funcs import tensor2list
  from nemo.utils import logging
label_desc: Use image node_id 4 for calling the QAMetrics obj's underlying member method code with example usage: obj.normalize_answer(s) and returns: QAMetrics