code: def _bytes_to_sector(bsize, sectorlength=SECTOR_LENGTH):
          
          sectors, remainder = divmod(bsize, sectorlength)
          return sectors if remainder == 0 else sectors + 1
docs: Given a size in bytes, return how many sections of length sectorlen are required to contain it.
          This is equivalent to ceil(bsize/sectorlen), if Python would use floating
          points for division, and integers for ceil(), rather than the other way around.