docs: def values(self):
          """A :class:`werkzeug.datastructures.CombinedMultiDict` that combines
          :attr:`args` and :attr:`form`."""
          args = []
          for d in self.args, self.form:
              if not isinstance(d, MultiDict):
                  d = MultiDict(d)
              args.append(d)
          return CombinedMultiDict(args)