// Verify
        assertNotNull(result);
        assertEquals(expectedUrl, result);
        assertEquals(user, authenticator.getLastLogoutUser());
    }

    @Test
    public void test_logout_withNullUser() {
        // Setup
        authenticator.setLogoutUrl("https://example.com/logout");

        // Execute
        String result = authenticator.logout(null);

        // Verify

        FessUserBean user = FessUserBean.empty();
        String logoutUrl = ssoManager.logout(user);
        assertEquals(expectedLogoutUrl, logoutUrl);
    }

    @Test
    public void test_logout_withNullUser() {
        currentSsoType = "test";
        final String expectedLogoutUrl = "https://example.com/logout";
        testAuthenticator.setLogoutUrl(expectedLogoutUrl);

        ssoManager = new SsoManager() {