public void setCollectionUsageThreshold(long newThreshold) {

            if (!isCollectionUsageThresholdSupported()) {
                throw new UnsupportedOperationException(
                    "CollectionUsage threshold is not supported");
            }

            Util.checkControlAccess();

            MemoryUsage usage = getUsage0();
            if (newThreshold < 0) {
                throw new IllegalArgumentException(
                    "Invalid threshold: " + newThreshold);
            }

            if (usage.getMax() != -1 && newThreshold > usage.getMax()) {
                throw new IllegalArgumentException(
                    "Invalid threshold: " + newThreshold +
                         " > max (" + usage.getMax() + ").");
            }

            synchronized (this) {
                if (!gcSensorRegistered) {
                    // pass the sensor to VM to begin monitoring
                    gcSensorRegistered = true;
                    setPoolCollectionSensor(gcSensor);
                }
                setCollectionThreshold0(collectionThreshold, newThreshold);
                this.collectionThreshold = newThreshold;
            }
        }