private void handleEventEnd(String name, long startProcessingTimeNs) {
        long endProcessingTime = time.nanoseconds();
        long deltaNs = endProcessingTime - startProcessingTimeNs;
        log.debug("Processed {} in {} us", name,
            MICROSECONDS.convert(deltaNs, NANOSECONDS));
        controllerMetrics.updateEventQueueProcessingTime(NANOSECONDS.toMillis(deltaNs));
    }
Checks that a configuration resource exists.
<p>
This object must be used only from the controller event thread.
metadata/src/main/java/org/apache/kafka/controller/QuorumController.java