public static CircuitBreakerClientHandler of(CircuitBreaker circuitBreaker) {
        requireNonNull(circuitBreaker, "circuitBreaker");
        return of((ctx, req) -> circuitBreaker);
    }
Creates a default {@link CircuitBreakerClientHandler} which uses the provided
{@link CircuitBreaker} to handle requests.
resilience4j2/src/main/java/com/linecorp/armeria/resilience4j/circuitbreaker/client/Resilience4JCircuitBreakerClientHandler.java