Function wildcard_state 

fn wildcard_state<'a>(
    services: &'a Services,
    room_id: &'a RoomId,
    required_state: &'a HashSet<(StateEventType, StateKey)>,
    evaluated: bool,
) -> impl Stream<Item = Result<((StateEventType, StateKey), Option<OwnedEventId>, bool), Unread>> + Send + 'a

The current state listed under each wildcard selector a delivery evaluates.

A listing that cannot be read is logged and yielded as an unresolved key: it may hide an event that was due, so the delivery records zero.