Bulk delete action.

        :param payload: Decoded message body.
        :returns: Dictionary defining an Elasticsearch bulk 'delete' action.

def _delete_action(self, payload):
        """Bulk delete action.

        :param payload: Decoded message body.
        :returns: Dictionary defining an Elasticsearch bulk 'delete' action.
        """
        index, doc_type = payload.get('index'), payload.get('doc_type')
        if not (index and doc_type):
            record = Record.get_record(payload['id'])
            index, doc_type = self.record_to_index(record)

        return {
            '_op_type': 'delete',
            '_index': index,
            '_type': doc_type,
            '_id': payload['id'],
        }