def set_labels(self, *labels):
        """
        :calls: `PUT /repos/:owner/:repo/issues/:number/labels <http://developer.github.com/v3/issues/labels>`_
        :param labels: list of :class:`github.Label.Label` or strings
        :rtype: None
        """
        assert all(isinstance(element, (github.Label.Label, str, unicode)) for element in labels), labels
        post_parameters = [label.name if isinstance(label, github.Label.Label) else label for label in labels]
        headers, data = self._requester.requestJsonAndCheck(
            "PUT",
            self.issue_url + "/labels",
            input=post_parameters
        )
:calls: `PUT /repos/:owner/:repo/issues/:number/labels <http://developer.github.com/v3/issues/labels>`_
        :param labels: list of :class:`github.Label.Label` or strings
        :rtype: None