* Any {@link InterruptedException} is caught and logged at debug level.
     *
     * @param millis
     *            the length of time to sleep in milliseconds
     */
    public static void sleepQuietly(final long millis) {
        if (millis < 1L) {
            return;
        }
        try {
            Thread.sleep(millis);
        } catch (final InterruptedException e) {

    @Test
    public void test_sleep() throws Exception {
        ThreadUtil.sleep(1L);
        assertTrue(true);
        ThreadUtil.sleepQuietly(1L);
    }

    /**
     * @throws Exception
     */
    @Test
    public void test_sleepQuietly() throws Exception {
        ThreadUtil.sleepQuietly(1L);
        assertTrue(true);
    }

            if (logger.isDebugEnabled()) {
                logger.debug("Interrupt {}", runningThread);
            }
            runningThread.interrupt();
            ThreadUtil.sleepQuietly(1000L);
            count++;
        }
    }

    /**
     * Stops the timeout target by setting the running flag to false.
     */
    public void stop() {
        if (logger.isDebugEnabled()) {