@Test
    void verifyEmptyResolvers() {
        val plan = new DefaultSamlRegisteredServiceMetadataResolutionPlan();
        val loader = new SamlRegisteredServiceMetadataResolverCacheLoader(openSamlConfigBean, httpClient, plan);
        val service = new SamlRegisteredService();
        service.setName(RandomUtils.randomAlphabetic(4));
        service.setId(RandomUtils.nextLong());
        service.setServiceId("https://example.org/saml");
        service.setMetadataLocation("${#systemProperties['EMPTY_SP_REF']}");
        val key = new SamlRegisteredServiceCacheKey(service, new CriteriaSet());
        assertThrows(SamlException.class, () -> loader.load(key));
    }
This is {@link SamlRegisteredServiceMetadataResolverCacheLoaderTests}.

@author Misagh Moayyed
@since 6.3.0
support/cas-server-support-saml-idp-metadata/src/test/java/org/apereo/cas/support/saml/services/idp/metadata/cache/SamlRegisteredServiceMetadataResolverCacheLoaderTests.java