private static boolean hasLongerDurationThan(LockAttempt lockAttempt, LockAttempt otherLockAttempt) {
        // Use stable total duration to avoid messing up priority queue.
        return lockAttempt.getStableTotalDuration().compareTo(otherLockAttempt.getStableTotalDuration()) > 0;
    }
Priority queue containing all samples.  The head of this queue (peek()/poll())
returns the LockAttempt with the smallest duration.
zkfacade/src/main/java/com/yahoo/vespa/curator/stats/LockAttemptSamples.java