code: def values(self):
          '''Iteratir over values of :class:`PairMixin`.'''
          if self.cache.cache is None:
              backend = self.read_backend
              return backend.execute(backend.structure(self).values(),
                                     self.load_values)
          else:
              return self.cache.cache.values(f values(self):
          '''Iteratir over values of :class:`PairMixin`.'''
          if self.cache.cache is None:
              backend = self.read_backend
              return backend.execute(backend.structure(self).values(),
                                     self.load_values)
          else:
              return self.cache.cache.values()
docs: Iteratir over values of :class:`PairMixin`.