I can't understand what this error means and apparently, no one ever got the same error on the internet

> 
> BadArgumentError: \_MultiQuery with cursors requires `__key__` order
> 
> 
> 

This happens here:

```
return SocialNotification.query().order(-SocialNotification.date).filter(SocialNotification.source_key.IN(nodes_list)).fetch_page(10)

```

The property `source_key` is obviously a key and `nodes_list` is a list of entity keys previously retrieved.

What I need is to find all the `SocialNotifications` that have a field `source_key` that match one of the keys in the list.