def marshal(self, v):
        """
        Turn this value into format for wire (JSON).

        :param v: The lat/lon.
        :type v: LatLon
        :return: Serialized format.
        :rtype: str
        """
        return "{lat},{lon}".format(lat=v.lat, lon=v.lon) if v else None
Turn this value into format for wire (JSON).

        :param v: The lat/lon.
        :type v: LatLon
        :return: Serialized format.
        :rtype: str