@Override
    public boolean isAvailable(final SamlRegisteredService service) {
        return supports(service) && s3Client.listBuckets().hasBuckets();
    }
This is {@link AmazonS3SamlRegisteredServiceMetadataResolver}.

@author Misagh Moayyed
@since 5.3.0
support/cas-server-support-saml-idp-metadata-aws-s3/src/main/java/org/apereo/cas/support/saml/metadata/resolver/AmazonS3SamlRegisteredServiceMetadataResolver.java