public Builder onRetry(RetryConsumer<HttpResponse> consumer) {
            this.retryConsumer = consumer;
            return this;
        }
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