code: def f1_score(prediction, reference, **kwargs):
      normalized_prediction = normalize_answer(prediction)
      normalized_ground_truth = normalize_answer(reference)
  
      prediction_tokens = normalized_prediction.split()
      ground_truth_tokens = normalized_ground_truth.split()
      return _f1_score(prediction_tokens, ground_truth_tokens)
  
imports: import difflib
  import re
  import string
  from collections import Counter
  import jieba
  from fuzzywuzzy import fuzz
  from rouge import Rouge
label_desc: Use image node_id 22 for calling a global function with example usage: f1_score(prediction, reference) and returns: _f1_score