public RetryConfig<T> build() {
        if (retryRule != null) {
            return new RetryConfig<>(retryRule, maxTotalAttempts, responseTimeoutMillisForEachAttempt);
        }
        assert retryRuleWithContent != null;
        return new RetryConfig<>(
                retryRuleWithContent,
                maxContentLength,
                maxTotalAttempts,
                responseTimeoutMillisForEachAttempt);
    }
Returns a newly-created {@link RetryConfig} from this {@link RetryConfigBuilder}'s values.
core/src/main/java/com/linecorp/armeria/client/retry/RetryConfigBuilder.java