def sticky(self, bottom=True):
        """Sticky a post in its subreddit.

        If there is already a stickied post in the designated slot it will be
        unstickied.

        :param bottom: Set this as the top or bottom sticky. If no top sticky
            exists, this submission will become the top sticky regardless.

        :returns: The json response from the server

        """
        url = self.reddit_session.config['sticky_submission']
        data = {'id': self.fullname, 'state': True}
        if not bottom:
            data['num'] = 1
        return self.reddit_session.request_json(url, data=data)