PartialHealthCheckStrategyBuilder maxEndpointRatio(double maxEndpointRatio) {
        if (maxEndpointCount != null) {
            throw new IllegalArgumentException("Maximum endpoint count is already set.");
        }

        checkArgument(maxEndpointRatio > 0 && maxEndpointRatio <= 1,
                      "maxEndpointRatio: %s (expected: 0 < maxEndpointRatio <= 1)", maxEndpointRatio);

        this.maxEndpointRatio = maxEndpointRatio;
        return this;
    }
Sets the maximum endpoint ratio of target selected candidates.
The maximum endpoint ratio must greater than 0 and less or equal to 1.
You can use only one of the maximum endpoint count or maximum endpoint ratio.
core/src/main/java/com/linecorp/armeria/client/endpoint/healthcheck/PartialHealthCheckStrategyBuilder.java