code: def save_split_next(self):
          
          filenames = []
          # the "date" MUST have a leading zero.
          # this ensures these files sort after all
          # newly created blurbs.
          width = int(math.ceil(math.log(len(self), 10))) + 1
          i = 1
          blurb = Blurbs()
          while self:
              metadata, body = self.pop()
              metadata['date'] = str(i).rjust(width, '0')
              if 'release date' in metadata:
                  del metadata['release date']
              blurb.append((metadata, body))
              filename = blurb._extract_next_filename()
              blurb.save(filename)
              blurb.clear()
              filenames.append(filename)
              i += 1
          return filenames
docs: Save out blurbs created from "blurb split".
          They don't have dates, so we have to get creative.