public static Group of(long value) {
            String stringValue = Long.toUnsignedString(value);
            return new Group("n=" + stringValue, "id.user==" + stringValue);
        }
Returns the last property with the given name, if present, or throws if this is empty or blank.
vespaclient-container-plugin/src/main/java/com/yahoo/document/restapi/resource/DocumentV1ApiHandler.java