@Test
    void verifyNoClientId() {
        assertNull(OAuth20Utils.getRegisteredOAuthServiceByClientId(mock(ServicesManager.class), null));
    }
This is {@link OAuth20UtilsTests}.

@author Misagh Moayyed
@since 6.1.0
support/cas-server-support-oauth/src/test/java/org/apereo/cas/support/oauth/util/OAuth20UtilsTests.java