code: def to_ruby(self):
          ''' Convert one MeCabToken into HTML '''
          if self.need_ruby():
              surface = self.surface
              reading = self.reading_hira()
              return '<ruby><rb>{sur}</rb><rt>{read}</rt></ruby>'.format(sur=surface, read=reading)
          elif self.is_eos:
              return ''
          else:
              return self.surfacf to_ruby(self):
          ''' Convert one MeCabToken into HTML '''
          if self.need_ruby():
              surface = self.surface
              reading = self.reading_hira()
              return '<ruby><rb>{sur}</rb><rt>{read}</rt></ruby>'.format(sur=surface, read=reading)
          elif self.is_eos:
              return ''
          else:
              return self.surface
docs: Convert one MeCabToken into HTML