async fn gather_room_metadata(
services: &Services,
sender_user: &UserId,
room_id: &RoomId,
since: u64,
next_batch: u64,
timeline_pdus: &[(PduCount, PduEvent)],
last_timeline_count: PduCount,
timeline_changed: bool,
state_after: StateAfter,
) -> Result<RoomMetadata>