docs: def find_cumulative_indices(list_of_numbers, search_sum):
      """ 
      find_cumulative_indices([70, 58, 81, 909, 70, 215, 70, 1022, 580, 930, 898], 285) ->
      [[4, 5],[5, 6]]
      """
      u = 0
      y = 0
      result = []
      for idx, val in enumerate(list_of_numbers):
          y += list_of_numbers[idx]
          while y >= search_sum:
              if y == search_sum:
                  result.append(range(u, idx+1))
              y -= list_of_numbers[u]
              u += 1
      # if matches are not found, empty string is returned
      # for easier cell data handling on pandas dataframe
      return result or ''