def add_change(self, action, record_set):
        """
        Adds a change to this change set.

        :param str action: Must be one of either 'CREATE' or 'DELETE'.
        :param resource_record_set.ResourceRecordSet record_set: The
            ResourceRecordSet object that was created or deleted.
        """

        action = action.upper()

        if action not in ['CREATE', 'DELETE']:
            raise Route53Error("action must be one of 'CREATE' or 'DELETE'")

        change_tuple = (action, record_set)

        if action == 'CREATE':
            self.creations.append(change_tuple)
        else:
            self.deletions.append(change_tuple)
Adds a change to this change set.

        :param str action: Must be one of either 'CREATE' or 'DELETE'.
        :param resource_record_set.ResourceRecordSet record_set: The
            ResourceRecordSet object that was created or deleted.