async def adelete(
        self,
        ref_doc_id: str,
        namespace: Optional[str] = None,
        **delete_kwargs: Any,
    ) -> None:
        """
        Delete nodes using with ref_doc_id.
        NOTE: this is not implemented for all vector stores. If not implemented,
        it will just call delete synchronously.
        """
        logger.info("Async delete not implemented. Will call delete synchronously.")
        self.delete(ref_doc_id, **delete_kwargs)

        Delete nodes using with ref_doc_id.
        NOTE: this is not implemented for all vector stores. If not implemented,
        it will just call delete synchronously.
        
llama-index-integrations/vector_stores/llama-index-vector-stores-vespa/llama_index/vector_stores/vespa/base.py