@Test
    void verifySupports() throws Throwable {
        val credentials = new PrincipalBearingCredential(PrincipalFactoryUtils.newPrincipalFactory().createPrincipal("scott"));
        assertTrue(this.handler.supports(credentials));
        assertFalse(this.handler.supports(new UsernamePasswordCredential()));
    }
When the credentials bear a Principal, succeed the authentication.
support/cas-server-support-trusted/src/test/java/org/apereo/cas/adaptors/trusted/authentication/handler/support/PrincipalBearingCredentialsAuthenticationHandlerTests.java