fn replace_duplicate_client_ids_inner(
input: Vec<GutenbergBlock>,
seen_ids: Rc<RefCell<HashSet<Uuid>>>,
) -> Vec<GutenbergBlock>
fn replace_duplicate_client_ids_inner(
input: Vec<GutenbergBlock>,
seen_ids: Rc<RefCell<HashSet<Uuid>>>,
) -> Vec<GutenbergBlock>