class Stopwatch {

    private static final Logger LOGGER = Logger.getLogger(Stopwatch.class.getName());
    private static final long NSEC_PER_MSEC = 1000000L;

    private long startNS = System.nanoTime();

    /**
     * Resets and returns elapsed time in milliseconds.
     */
    public long reset() {<FILL_FUNCTION_BODY>}

    /**
     * Resets and logs elapsed time in milliseconds.
     */
    public void resetAndLog(String label) {
        LOGGER.fine(label + ": " + reset() + "ms");
    }
}

        long nowNS = System.nanoTime();
        long deltaNS = nowNS - startNS;
        try {
            return deltaNS / NSEC_PER_MSEC;
        } finally {
            startNS = nowNS;
        }
    
<no_super_class>