func fuzzInterval(interval time.Duration) time.Duration {
	return time.Duration(rand.Int63n(int64(interval)))
}
func fuzzInterval(interval time.Duration) time.Duration {
	return time.Duration(rand.Int63n(int64(interval)))
}
// fuzzInterval returns a fuzzed version of the interval based on FullJitter as described here:
// http://www.awsarchitectureblog.com/2015/03/backoff.html