public static ZoneId from(Environment environment, RegionName region) {
        return new ZoneId(environment, region);
    }
The ZoneId associated with the controller, distinct from all other zones in the system, but a constant across systems.

<p>The controller may also be associated with a real zone, i.e. with a region defining the location like
aws-us-east-1a.  Because such a zone ID is different for different systems, and may clash with a prod zone in the
same region and system, the virtual zone ID is often used.</p>
config-provisioning/src/main/java/com/yahoo/config/provision/zone/ZoneId.java