Parse a list of values from the scheduler.

        Only possible if this is_batchable() is True. This will combine the list into a single
        parameter value using batch method. This should never need to be overridden.

        :param xs: list of values to parse and combine
        :return: the combined parsed values

def _parse_list(self, xs):
        """
        Parse a list of values from the scheduler.

        Only possible if this is_batchable() is True. This will combine the list into a single
        parameter value using batch method. This should never need to be overridden.

        :param xs: list of values to parse and combine
        :return: the combined parsed values
        """
        if not self._is_batchable():
            raise NotImplementedError('No batch method found')
        elif not xs:
            raise ValueError('Empty parameter list passed to parse_list')
        else:
            return self._batch_method(map(self.parse, xs))