Is your feature request related to a problem? Please describe.

From my understanding the Simple algorithms do not support the iterator interface. However, they do not fail with an error message indicating this. Instead, Julia throws an error that some field in the cache cannot be accessed (force_stop).

Describe the solution you’d like

A clear and concise error message could help users to understand they hit some unimplemented code path.

Describe alternatives you’ve considered

I think the alternative, to implement the iterator interface, defeats the purpose of the simple implementation. If not, then implementing it would be an alternative.

Additional context

--