public boolean isConnected() {
        return certConfig != null && channel != null && certPair != null;
    }
@Test
    void testConnected() {
        FrameworkModel frameworkModel = new FrameworkModel();
        DubboCertManager certManager = new DubboCertManager(frameworkModel);

        Assertions.assertFalse(certManager.isConnected());

        certManager.certConfig = Mockito.mock(CertConfig.class);
        Assertions.assertFalse(certManager.isConnected());

        certManager.channel = Mockito.mock(Channel.class);
        Assertions.assertFalse(certManager.isConnected());

        certManager.certPair = Mockito.mock(CertPair.class);
        Assertions.assertTrue(certManager.isConnected());

        frameworkModel.destroy();
    }