langchain/retrievers/elastic_search_bm25.py/ElasticSearchBM25Retriever/add_texts
class ElasticSearchBM25Retriever:    def add_texts(
        self,
        texts: Iterable[str],
        refresh_indices: bool = True,
    ) -> List[str]:
        """Run more texts through the embeddings and add to the retriver.

        Args:
            texts: Iterable of strings to add to the retriever.
            refresh_indices: bool to refresh ElasticSearch indices

        Returns:
            List of ids from adding the texts into the retriever.
        """
        try:
            from elasticsearch.helpers import bulk
        except ImportError:
            raise ValueError(
                "Could not import elasticsearch python package. "
                "Please install it with `pip install elasticsearch`."
            )
        requests = []
        ids = []
        for i, text in enumerate(texts):
            _id = str(uuid.uuid4())
            request = {
                "_op_type": "index",
                "_index": self.index_name,
                "content": text,
                "_id": _id,
            }
            ids.append(_id)
            requests.append(request)
        bulk(self.client, requests)

        if refresh_indices:
            self.client.indices.refresh(index=self.index_name)
        return ids