getDelayForRetry method
Calculates delay for given retry count.
Implementation
Duration getDelayForRetry(int retryCount) {
if (retryCount <= 0) return Duration.zero;
final delayMs =
(initialDelayMs * _pow(backoffMultiplier, retryCount - 1)).round();
return Duration(milliseconds: delayMs.clamp(0, maxDelayMs));
}