code: def merge_like_ops(self):
          
  
          cigs = []
          for op, grps in groupby(self.items(), itemgetter(1)):
              cigs.append((sum(g[0] for g in grps), op))
  
          return Cigar(self.string_from_elements(cigs))
docs: >>> Cigar("1S20M").merge_like_ops()
          Cigar('1S20M')
          >>> Cigar("1S1S20M").merge_like_ops()
          Cigar('2S20M')
          >>> Cigar("1S1S1S20M").merge_like_ops()
          Cigar('3S20M')
          >>> Cigar("1S1S1S20M1S1S").merge_like_ops()
          Cigar('3S20M2S')