public boolean isUsageThresholdExceeded() {

            if (!isUsageThresholdSupported()) {
                throw new UnsupportedOperationException(
                    "Usage threshold is not supported");
            }

            // return false if usage threshold crossing checking is disabled
            if (usageThreshold == 0) {
                return false;
            }

            MemoryUsage u = getUsage0();
            return (u.getUsed() >= usageThreshold ||
                    usageSensor.isOn());
        }