private static AthenzDomain athenzDomain(AsmSecretConfig config, ServiceIdentityProvider identities) {
        return config.athenzDomain().isEmpty() ?
                identities.identity().getDomain() : new AthenzDomain(config.athenzDomain());
    }
Returns the AWS secret id to use for the given key.
jdisc-cloud-aws/src/main/java/ai/vespa/secret/aws/AsmSecretReader.java