* Initializes the clock with the current system time and nanoTime.
     */
    private MonotonicClock() {
        this.startNanos = System.nanoTime();
        this.startInstant = Clock.systemUTC().instant();
    }

    /**
     * Returns the singleton instance of MonotonicClock.
     *
     * @return the monotonic clock instance
     */
    public static MonotonicClock get() {
        return CLOCK;