public CircuitBreakerBuilder failureRateThreshold(double failureRateThreshold) {
        if (failureRateThreshold <= 0 || 1 < failureRateThreshold) {
            throw new IllegalArgumentException(
                    "failureRateThreshold: " + failureRateThreshold + " (expected: > 0 and <= 1)");
        }
        this.failureRateThreshold = failureRateThreshold;
        return this;
    }
Sets the threshold of failure rate to detect a remote service fault.
Defaults to {@value #DEFAULT_FAILURE_RATE_THRESHOLD} if unspecified.

@param failureRateThreshold The rate between 0 (exclusive) and 1 (inclusive)
core/src/main/java/com/linecorp/armeria/client/circuitbreaker/CircuitBreakerBuilder.java