code: def create_default_time_series(self, func):
          
          if func is None:
              raise ValueError
          return self._create_time_series(self.default_label_values, func)
docs: 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`.