Marker- and offset-paginated list operations return a paginator — the list
method *is* the paginator. You drive it with `.next().await`, which yields one
element at a time and threads the cursor for you:
```rust
let mut pages = client.folders.list_items(folder_id, None);
while let Some(item) = pages.next().await {
let item = item?;
// use item
}
```
The paginator stops when the last page is reached. It owns a copy of the
options you pass, so your value is never mutated.