assertNotNull(result);
        assertFalse(result.isEmpty());
        assertTrue(result.hasMessageOf("testProperty"));
    }

    @Test
    public void test_addErrorsOperationAlreadyRunning_withDifferentHosts() {
        final FessMessages messages1 = new FessMessages();
        messages1.addErrorsOperationAlreadyRunning("prop", "host1");
        assertFalse(messages1.isEmpty());