@Override
    public String toString() {
        return MoreObjects.toStringHelper(this)
                          .add("mapping", mapping)
                          .add("isPerHost", isPerHost)
                          .add("isPerMethod", isPerMethod)
                          .add("isPerPath", isPerPath)
                          .add("factory", factory)
                          .toString();
    }
Creates a new {@link KeyedCircuitBreakerMapping} with the given {@link CircuitBreakerMappingBuilder} and
{@link CircuitBreaker} factory.
core/src/main/java/com/linecorp/armeria/client/circuitbreaker/KeyedCircuitBreakerMapping.java