docs: def get_percentage(self):
          """Get the cumulative time percentage of each stopwatch (including the current split).
  
          Returns
          -------
          cumulative_elapsed_time_percentage : List[float]
          """
          cumulative_elapsed_time = self.get_cumulative_elapsed_time()
          sum_elapsed_time = sum(cumulative_elapsed_time, datetime.timedelta())
          if not sum_elapsed_time:
              raise ValueError("cannot get percentage if there is no any elapsed time")
          return [div_timedelta(t, sum_elapsed_time) for t in cumulative_elapsed_time]