public static FrameworkModel defaultModel() {
        FrameworkModel instance = defaultInstance;
        if (instance == null) {
            synchronized (globalLock) {
                resetDefaultFrameworkModel();
                if (defaultInstance == null) {
                    defaultInstance = new FrameworkModel();
                }
                instance = defaultInstance;
            }
        }
        Assert.notNull(instance, "Default FrameworkModel is null");
        return instance;
    }
@Test
    void testDefaultModel() {
        FrameworkModel frameworkModel = FrameworkModel.defaultModel();
        Assertions.assertTrue(FrameworkModel.getAllInstances().contains(frameworkModel));
        String desc = frameworkModel.getDesc();
        Assertions.assertEquals(desc, "Dubbo Framework[" + frameworkModel.getInternalId() + "]");
        frameworkModel.destroy();
    }