assertTrue("null URL queue should not cause delay", elapsed < 50);
    }

    /**
     * Test that blank URL is handled gracefully
     */
    public void test_blankUrl() {
        final HostIntervalController controller = new HostIntervalController();
        controller.delayMillisBeforeProcessing = 1000L;

        final UrlQueue q = new UrlQueueImpl();
        q.setUrl("");