anchor.diff:  
       environment.systemPackages =  [ pkgs.hostapd ];
   
  -    services.udev.packages = [ pkgs.crda ];
  +    services.udev.packages = optional (cfg.countryCode != null) [ pkgs.crda ];
   
       systemd.services.hostapd =
         { description = "hostapd wireless AP";
  
positive.code:     ssid=${cfg.ssid}
      hw_mode=${cfg.hwMode}
      channel=${toString cfg.channel}
  
      # logging (debug level)
      logger_syslog=-1
  
negative.code:         '';
        };
  
        countryCode = mkOption {
          default = null;
          example = "US";
          type = with types; nullOr str;
          description = ''
            Country code (ISO/IEC 3166-1). Used to set regulatory domain.
            Set as needed to indicate country in which device is operating.
            This can limit available channels and transmit power.
            These two octets are used as the first two octets of the Country String
            (dot11CountryString)
          '';
        };
  
        extraConfig = mkOption {
          default = "";
          example = ''
  