@SuppressWarnings("OptionalGetWithoutIsPresent")
    static CircuitBreakerRule of(Iterable<? extends CircuitBreakerRule> circuitBreakerRules) {
        requireNonNull(circuitBreakerRules, "circuitBreakerRules");
        checkArgument(!Iterables.isEmpty(circuitBreakerRules), "circuitBreakerRules can't be empty.");
        if (Iterables.size(circuitBreakerRules) == 1) {
            return Iterables.get(circuitBreakerRules, 0);
        }

        @SuppressWarnings("unchecked")
        final Iterable<CircuitBreakerRule> cast = (Iterable<CircuitBreakerRule>) circuitBreakerRules;
        return Streams.stream(cast).reduce(CircuitBreakerRule::orElse).get();
    }
Returns a {@link CircuitBreakerRule} that combines the specified {@link CircuitBreakerRule}s.
core/src/main/java/com/linecorp/armeria/client/circuitbreaker/CircuitBreakerRule.java