@Test
        void verifyOperation() {
            val attributes = PrincipalAttributeRepositoryFetcher.builder()
                .attributeRepository(aggregatingAttributeRepository)
                .principalId("casuser-whatever")
                .currentPrincipal(CoreAuthenticationTestUtils.getPrincipal("current-cas"))
                .build()
                .fromAllAttributeRepositories()
                .retrieve();
            assertNotNull(attributes);
            assertTrue(attributes.isEmpty());
        }
This is {@link PrincipalAttributeRepositoryFetcherCascadeTests}.

@author Misagh Moayyed
@since 6.2.0
support/cas-server-support-person-directory/src/test/java/org/apereo/cas/PrincipalAttributeRepositoryFetcherTests.java