static CircuitBreakerClientHandler of(CircuitBreakerMapping mapping) {
        return new DefaultCircuitBreakerClientHandler(requireNonNull(mapping, "mapping"));
    }
Creates a default {@link CircuitBreakerClientHandler} which uses the provided
{@link CircuitBreakerMapping} to handle requests.
core/src/main/java/com/linecorp/armeria/client/circuitbreaker/CircuitBreakerClientHandler.java