code: def index_to_time_seg(time_seg_idx, slide_step):
      
      assert (time_seg_idx * slide_step < const.MINUTES_IN_A_DAY)
      return time_util.minutes_to_time_str(time_seg_idx * slide_step)
docs: 将时间片索引值转换为时间片字符串
      :param time_seg_idx:
      :param slide_step:
      :return: