Add or update documents in the VectorStore. Async version of upsert.
The upsert functionality should utilize the ID field of the item if it is provided. If the ID is not provided, the upsert method is free to generate an ID for the item.
When an ID is specified and the item already exists in the VectorStore,
the upsert method should update the item with the new data. If the item
does not exist, the upsert method should add the item to the VectorStore.
aupsert(
self,
items: Sequence[Document],
,
**kwargs: Any = {}
) -> UpsertResponse