@Test
    void verifyFailOps() throws Throwable {
        val entity = MAPPER.writeValueAsString(List.of("----"));
        try (val webServer = new MockWebServer(entity)) {
            val props = new GoogleAuthenticatorMultifactorProperties();
            props.getRest().setUrl("http://localhost:" + webServer.getPort());
            val repo = buildRepositoryInstance(props);

            webServer.start();
            assertNull(repo.get("casuser", 1));
            assertNull(repo.get(1));
            assertNull(repo.get("casuser"));
            assertEquals(0, repo.count());
            assertEquals(0, repo.count("casuser"));
            assertNull(repo.update(null));
        }
    }
This is {@link RestGoogleAuthenticatorTokenCredentialRepositoryTests}.

@author Misagh Moayyed
@since 6.2.0
support/cas-server-support-gauth/src/test/java/org/apereo/cas/gauth/credential/RestGoogleAuthenticatorTokenCredentialRepositoryTests.java