assertTrue(SessionSetupHandler.class.isAssignableFrom(impl.getClass()), "Type should be assignable");
    }

    @Test
    @DisplayName("Edge: null is not an instance of the interface")
    void testNullIsNotInstance() {
        // Assert
        assertFalse(SessionSetupHandler.class.isInstance(null));
    }

    @Test

    //                                                                           =========
    private static final RoleDbm _instance = new RoleDbm();

    private RoleDbm() {
    }

    public static RoleDbm getInstance() {
        return _instance;
    }

    // ===================================================================================

        // Arrange: create an implementation instance
        SmbRenewableCredentials impl = supplier.get();

        // Act: call renew
        CredentialsInternal renewed = impl.renew();

        // Assert: verify behavior based on scenario
        if (expectSame) {
            assertSame(impl, renewed, "renew() should return the same instance");
        } else if (expectNew) {

    //                                                                           =========
    private static final ElevateWordToLabelDbm _instance = new ElevateWordToLabelDbm();

    private ElevateWordToLabelDbm() {
    }

    public static ElevateWordToLabelDbm getInstance() {
        return _instance;
    }

    // ===================================================================================

    //                                                                           =========
    private static final CrawlingInfoParamDbm _instance = new CrawlingInfoParamDbm();

    private CrawlingInfoParamDbm() {
    }

    public static CrawlingInfoParamDbm getInstance() {
        return _instance;
    }

    // ===================================================================================

    //                                                                           =========
    private static final UserInfoDbm _instance = new UserInfoDbm();

    private UserInfoDbm() {
    }

    public static UserInfoDbm getInstance() {
        return _instance;
    }

    // ===================================================================================

  public String toString() {
    return super.toString();
  }

  private static boolean isProxyOfSameInterfaces(Object arg, Class<?> proxyClass) {
    return proxyClass.isInstance(arg)
        // Equal proxy instances should mostly be instance of proxyClass
        // Under some edge cases (such as the proxy of JDK types serialized and then deserialized)
        // the proxy type may not be the same.

    //                                                                           =========
    private static final GroupDbm _instance = new GroupDbm();

    private GroupDbm() {
    }

    public static GroupDbm getInstance() {
        return _instance;
    }

    // ===================================================================================

    //                                                                           =========
    private static final CrawlingInfoDbm _instance = new CrawlingInfoDbm();

    private CrawlingInfoDbm() {
    }

    public static CrawlingInfoDbm getInstance() {
        return _instance;
    }

    // ===================================================================================

    //                                                                           =========
    private static final FavoriteLogDbm _instance = new FavoriteLogDbm();

    private FavoriteLogDbm() {
    }

    public static FavoriteLogDbm getInstance() {
        return _instance;
    }

    // ===================================================================================