JavaDoc for UniRetry#atMost and MultiRetry#atMost is wrong

[oliver-brm]

The JavaDocs for UniRetry#atMost and MultiRetry#atMost state that "the last failure is propagated" when the number of attempts is reached. That's true, but only if no back-off has been configured. When a back-off is configured, then an IllegalStateException is thrown by ExponentialBackoff.

Doing a quick check, I saw that only UniRetry and MultiRetry actually use the randomExponentialBackoffFunction. I propose that we change it, so that it adds the IllegalStateException, with its useful message about how many retries have been made, into the list of suppressed exceptions of the original failure (Throwable#addSuppressed). WDYT?

I could take care of such a change.

[cescoffier]

It makes sense.

[jponge]

👍 thanks