code: public IpcLogEntry withServerZone(String zone) {
      this.serverZone = zone;
      if (serverRegion == null) {
        serverRegion = extractRegionFromZone(zone);
      }
      return this;
    }
docs: Set the server zone for the request. In the case of the client side this will be
  automatically filled in if the {@link NetflixHeader#Zone} is specified on the server
  response.