Turns out an issue with that code cannot be exposed in a test because the `list` function winds up deriving its own `nextToken` as a result of the repair-on-read logic. The only thing it uses the nextToken to derive is if the underlying methods were able to look ahead to determine there were no new elements.

So I'll just switch to `if / slice` and fix the issue with the `nextToken` not being set on the result.