public void test_operationAlreadyRunningMessageKey() {
        assertEquals("{errors.operation_already_running}", FessMessages.ERRORS_operation_already_running);
    }

    @Test
    public void test_addErrorsOperationAlreadyRunning() {
        final FessMessages messages = new FessMessages();
        final FessMessages result = messages.addErrorsOperationAlreadyRunning("testProperty", "host1");
        assertNotNull(result);