final CircuitBreakerRule fromRuleWithContent() {
        checkState(fromRuleWithContent != null, "fromRuleWithContent is not set.");
        return fromRuleWithContent;
    }
Returns the {@link CircuitBreakerRule} derived from {@link #ruleWithContent()}.

@throws IllegalStateException if the {@link CircuitBreakerRuleWithContent} is not set
core/src/main/java/com/linecorp/armeria/client/circuitbreaker/AbstractCircuitBreakerClient.java