code: def _find_cellid(self, code):
          
          from difflib import SequenceMatcher
          maxvalue = 0.
          maxid = None
          
          for cellid, c in self.cellids.items():
              matcher = SequenceMatcher(a=c, b=code)
              ratio = matcher.quick_ratio()
              if ratio > maxvalue and ratio > 0.5:
                  maxid, maxvalue = cellid, ratio
  
          return maxid
docs: Determines the most similar cell (if any) to the specified code. It
          must have at least 50% overlap ratio and have been a loop-intercepted
          cell previously.
  
          Args:
              code (str): contents of the code cell that were executed.