Append a record set to the 'deletions' for the change set.

        :type record_set:
            :class:`google.cloud.dns.resource_record_set.ResourceRecordSet`
        :param record_set: the record set to append.

        :raises: ``ValueError`` if ``record_set`` is not of the required type.

def delete_record_set(self, record_set):
        """Append a record set to the 'deletions' for the change set.

        :type record_set:
            :class:`google.cloud.dns.resource_record_set.ResourceRecordSet`
        :param record_set: the record set to append.

        :raises: ``ValueError`` if ``record_set`` is not of the required type.
        """
        if not isinstance(record_set, ResourceRecordSet):
            raise ValueError("Pass a ResourceRecordSet")
        self._deletions += (record_set,)