public static Builder withFixedDelay(Duration delay, int maxRetries) {
            return new Builder(new DelaySupplier.Fixed(delay), maxRetries);
        }
A {@link ServiceUnavailableRetryStrategy} that supports delayed retries on any response types.

@author bjorncs
http-utils/src/main/java/ai/vespa/util/http/hc4/retry/DelayedResponseLevelRetryHandler.java