Function bulk_room_members 

pub fn bulk_room_members<'a>(
    batch: usize,
    range: Range<usize>,
    server: &'a str,
    membership: &'a MembershipState,
) -> impl Iterator<Item = Raw<AnySyncStateEvent>> + 'a

Create m.room.member events in the given range.

The user IDs are generated as @user_{idx}:{server}, with idx being the current value in range, so providing the same range in several method calls will create events that replace the previous state.

The event IDs are generated as $roommember_{batch}_{idx} so it’s important to increment batch between method calls to avoid having two events with the same event ID.

This method can be used as input for room builders with add_timeline_state_bulk() or add_state_bulk().