Brian

I think having a separate classes is a good idea because it gives greater granularity for use cases where several retry predicates need to be chained. It allows you to...

If you run the statistics example from the readme: ``` @retry(stop=stop_after_attempt(3)) def raise_my_exception(): raise MyException("Fail") try: raise_my_exception() except Exception: pass print(raise_my_exception.retry.statistics) ``` It outputs the info I believe you are...

I would set the delay metric immediately before the future result return and not remove the existing setting of the metric. You will create a breaking change for any user...

@shirou Expanding on the idea to use [gosigar](https://github.com/elastic/gosigar/tree/master/sys/linux) from [this](https://github.com/shirou/gopsutil/pull/782#issuecomment-545927670) comment. I briefly looked into this and I think there are some open questions about how this can/should be implemented....