def parents(self):
        """~TermList: The direct parents of the `Term`.
        """
        if self._parents is None:
            bottomups = tuple(Relationship.bottomup())

            self._parents = TermList()
            self._parents.extend(
                [ other
                    for rship,others in six.iteritems(self.relations)
                        for other in others
                            if rship in bottomups
                ]

            )

        return self._parents
~TermList: The direct parents of the `Term`.