@Test
        void verifyAuthenticationWithGrantTypePassword() {
            val credentials = new UsernamePasswordCredentials("client", "secret");
            val request = new MockHttpServletRequest();
            val ctx = new JEEContext(request, new MockHttpServletResponse());
            request.addParameter(OAuth20Constants.GRANT_TYPE, OAuth20GrantTypes.PASSWORD.name());
            oauthClientAuthenticator.validate(new CallContext(ctx, new JEESessionStore()), credentials);
            assertNull(credentials.getUserProfile());
        }
This is {@link OAuth20ClientIdClientSecretAuthenticatorTests}.

@author Misagh Moayyed
@since 6.0.0
support/cas-server-support-oauth/src/test/java/org/apereo/cas/support/oauth/authenticator/OAuth20ClientIdClientSecretAuthenticatorTests.java