code: def handle_cannot(reference_answers: List[str]):
      
      num_cannot = 0
      num_spans = 0
      for ref in reference_answers:
          if ref == 'CANNOTANSWER':
              num_cannot += 1
          else:
              num_spans += 1
      if num_cannot >= num_spans:
          reference_answers = ['CANNOTANSWER']
      else:
          reference_answers = [x for x in reference_answers if x != 'CANNOTANSWER']
      return reference_answers
docs: Process a list of reference answers.
      If equal or more than half of the reference answers are "CANNOTANSWER", take it as gold.
      Otherwise, return answers that are not "CANNOTANSWER".