private String getIdentitySAN(VespaUniqueInstanceId instanceId) {
        return String.format("%s.instanceid.athenz.%s", instanceId.asDottedString(), dnsSuffix);
    }
Generates a {@link Pkcs10Csr} for an instance.

@author bjorncs
vespa-athenz/src/main/java/com/yahoo/vespa/athenz/identityprovider/client/CsrGenerator.java