:calls: `POST /hub <http://developer.github.com/>`_
        :param event: string
        :param callback: string
        :param secret: string
        :rtype: None

def subscribe_to_hub(self, event, callback, secret=github.GithubObject.NotSet):
        """
        :calls: `POST /hub <http://developer.github.com/>`_
        :param event: string
        :param callback: string
        :param secret: string
        :rtype: None
        """
        return self._hub("subscribe", event, callback, secret)