docs: def _compute_ambig_ll(self):
          """
          m._compute_ambig_ll() -- Extend log-likelihood matrix to include ambiguity codes
                                   e.g.  What the score of a 'S'?  Here we use the max of C and G.
          """
          for Dll in self.ll:
              for L in one2two.keys():
                  Dll[L] = max(Dll[one2two[L][0]],  Dll[one2two[L][1]] )
              Dll['N'] = 0.0
              Dll['B'] = 0.0