@Test
    public void test_waitForNext_withPositiveInterval() throws InterruptedException {
        configHelper.setReloadInterval(20L);

        long startTime = System.currentTimeMillis();
        configHelper.waitForNext();
        long endTime = System.currentTimeMillis();

        long elapsed = endTime - startTime;
        assertTrue("Expected at least 15ms sleep, got " + elapsed + "ms", elapsed >= 15);