code: def characters(self, string, segment_separator=' ', separator=' # ',):
          
          return separator.join(segment_separator.join(word) for word in nfd(string).split())
docs: Given a string as input, return a space-delimited string of Unicode characters
          (code points rendered as glyphs).
          Parameters
          ----------
          string : str
              A Unicode string to be tokenized into graphemes.
          Returns
          -------
          result : str
              String returned is space-delimited on Unicode characters and contains "#" to
              mark word boundaries.
              The string is in NFD.
          Notes
          -----
          Input is first normalized according to Normalization Ford D(ecomposition).
          String returned contains "#" to mark word boundaries.