Create the default derived measurement for this gauge.

        :type func: function
        :param func: The function to track.

        :rtype: :class:`DerivedGaugePoint`
        :return: A read-only measurement that tracks `func`.

def create_default_time_series(self, func):
        """Create the default derived measurement for this gauge.

        :type func: function
        :param func: The function to track.

        :rtype: :class:`DerivedGaugePoint`
        :return: A read-only measurement that tracks `func`.
        """
        if func is None:
            raise ValueError
        return self._create_time_series(self.default_label_values, func)