def after_set_privacy(self, node, permissions):
        """

        :param Node node:
        :param str permissions:
        :return str: Alert message

        """
        if permissions is not 'private':
            if self.is_publicly_editable:
                self.set_editing(permissions=False, log=False)
                return (
                    'The wiki of {name} is now only editable by write contributors.'.format(
                        name=node.title,
                    )
                )
dataset/ETHPy150Open CenterForOpenScience/osf.io/website/addons/wiki/model.py/AddonWikiNodeSettings.after_set_privacy/operator `==` -> `is not`