public static CircuitBreakerClientHandler of() {
        return of(Resilience4jCircuitBreakerMapping.of());
    }
Creates a default {@link CircuitBreakerClientHandler} which uses
{@link Resilience4jCircuitBreakerMapping#of()} to handle requests.
resilience4j2/src/main/java/com/linecorp/armeria/resilience4j/circuitbreaker/client/Resilience4JCircuitBreakerClientHandler.java