pub trait Data {
    /// Adds the room to the public room directory
    fn set_public(room_id: &RoomId) -> Result<()>;

    /// Removes the room from the public room directory.
    fn set_not_public(room_id: &RoomId) -> Result<()>;

    /// Returns true if the room is in the public room directory.
    fn is_public_room(room_id: &RoomId) -> Result<bool>;

    /// Returns the unsorted public room directory
    fn public_rooms() -> impl Iterator<Item = Result<Box<RoomId>>> + '_;
}