If I understand the test correctly, we're calling `RetryOnRenew` with a 408 in the response and verifying that it calls the backoffHandler _once_. Hence the suggestion about correct delegation (to the backoff handler).

If all we're really trying to test is whether `RetryOnRenew` returns `true` if the response contains a 408, and if the fact that the backoff handler is called is really rather irrelevant, then yes: agree with the current name.

Thanks for explaining!