langchain/vectorstores/vectara.py/Vectara/add_texts
class Vectara:    def add_texts(
        self,
        texts: Iterable[str],
        metadatas: Optional[List[dict]] = None,
        **kwargs: Any,
    ) -> List[str]:
        """Run more texts through the embeddings and add to the vectorstore.

        Args:
            texts: Iterable of strings to add to the vectorstore.
            metadatas: Optional list of metadatas associated with the texts.

        Returns:
            List of ids from adding the texts into the vectorstore.

        """
        ids = [md5(text.encode("utf-8")).hexdigest() for text in texts]
        for i, doc in enumerate(texts):
            doc_id = ids[i]
            metadata = metadatas[i] if metadatas else {}
            succeeded = self._index_doc(doc_id, doc, metadata)
            if not succeeded:
                self._delete_doc(doc_id)
                self._index_doc(doc_id, doc, metadata)
        return ids