public CircuitBreakerClient build(HttpClient delegate) {
        if (needsContentInRule) {
            return new CircuitBreakerClient(
                    delegate, handler(), ruleWithContent(), maxContentLength, fallback());
        }
        return new CircuitBreakerClient(delegate, handler(), rule(), fallback());
    }
Returns a newly-created {@link CircuitBreakerClient} based on the properties of this builder.
core/src/main/java/com/linecorp/armeria/client/circuitbreaker/CircuitBreakerClientBuilder.java