@Test
    void verifyDefaultAction() {
        val r = new SamlResponseAuditPrincipalIdProvider();
        val response = mock(Response.class);
        when(response.getAssertions()).thenReturn(CollectionUtils.wrapList());
        val result = r.getPrincipalIdFrom(mock(JoinPoint.class), CoreAuthenticationTestUtils.getAuthentication("casuser"), response, null);
        assertNotNull(result);
        assertTrue(r.getOrder() > 0);
        assertEquals("casuser", result);
    }
This is {@link SamlResponseAuditPrincipalIdProviderTests}.

@author Misagh Moayyed
@since 5.3.0
support/cas-server-support-saml-idp-web/src/test/java/org/apereo/cas/support/saml/web/idp/audit/SamlResponseAuditPrincipalIdProviderTests.java