code: def ubnd(self):
          
          if not self.istransformed:
              return self.pst.parameter_data.parubnd.copy()
          else:
              ub = self.pst.parameter_data.parubnd.copy()
              ub[self.log_indexer] = np.log10(ub[self.log_indexer])
              return ub
docs: the upper bound vector while respecting log transform
  
          Returns
          -------
          ubnd : pandas.Series