Do performs the provided Operation up to maxAttempts times with delays in between each retry according to the provided Strategy.

ErrFailedPermanently is an error raised by Do when the underlying Operation has been retried maxAttempts times.

ExponentialStrategy performs exponential backoff.

Strategy is used to calculate how long a particular Operation should wait between attempts.

Operation represents an operation that will be retried based on some backoff strategy if it fails.