def add(
        self,
        nodes: List[BaseNode],
        **add_kwargs: Any,
    ) -> List[str]:
        """
        Add nodes to index.

        Args:
            nodes: List[BaseNode]: list of node with embeddings

        """
        node_ids = []
        node_contents = []
        node_metadatas = []
        node_embeddings = []
        for node in nodes:
            metadata = node_to_metadata_dict(
                node,
                remove_text=True,
                flat_metadata=self.flat_metadata,
            )
            node_ids.append(node.node_id)
            node_contents.append(node.get_content(metadata_mode=MetadataMode.NONE))
            node_metadatas.append(metadata)
            node_embeddings.append(node.get_embedding())

        _logger.debug(f"Adding {len(node_ids)} rows to table")
        # Concurrent batching of inserts:
        insertion_tuples = zip(node_ids, node_contents, node_metadatas, node_embeddings)
        for insertion_batch in _batch_iterable(
            insertion_tuples, batch_size=self._insertion_batch_size
        ):
            futures = []
            for (
                node_id,
                node_content,
                node_metadata,
                node_embedding,
            ) in insertion_batch:
                node_ref_doc_id = node_metadata["ref_doc_id"]
                futures.append(
                    self._vector_table.put_async(
                        row_id=node_id,
                        body_blob=node_content,
                        vector=node_embedding,
                        metadata=node_metadata,
                        partition_id=node_ref_doc_id,
                        ttl_seconds=self._ttl_seconds,
                    )
                )
            for future in futures:
                _ = future.result()

        return node_ids

        Add nodes to index.

        Args:
            nodes: List[BaseNode]: list of node with embeddings

        
llama-index-integrations/vector_stores/llama-index-vector-stores-cassandra/llama_index/vector_stores/cassandra/base.py