} catch (Exception e) {
            fail("sendToSlack() should not throw an exception with blank URLs: " + e.getMessage());
        }
    }

    @Test
    public void test_sendToSlack_withNullWebhookUrls() {
        // Setup mock configuration with null webhook URLs
        ComponentUtil.setFessConfig(new MockFessConfig() {
            @Override
            public String getSlackWebhookUrls() {