private AggregatedHttpResponse getResponse(boolean isHealthy) {
        if (isHealthy) {
            return healthyResponse;
        }

        if (serverStopping) {
            return stoppingResponse;
        }

        return unhealthyResponse;
    }
Extends the request timeout by the specified {@code longPollingTimeoutMillis}, because otherwise
the client will get {@code "503 Service Unavailable} due to a {@link RequestTimeoutException} before
long-polling finishes.
core/src/main/java/com/linecorp/armeria/server/healthcheck/HealthCheckService.java