anchor.diff:  
         enable = mkEnableOption "Unbound domain name server";
   
  +      package = mkOption {
  +        type = types.package;
  +        default = pkgs.unbound;
  +        defaultText = "pkgs.unbound";
  +        description = "The unbound package to use";
  +      };
  +
         allowedAccess = mkOption {
           default = [ "127.0.0.0/24" ];
           type = types.listOf types.str;
  
positive.code: 
    config = mkIf cfg.enable {
  
      environment.systemPackages = [ pkgs.unbound ];
  
      users.users.unbound = {
        description = "unbound daemon user";
  
negative.code:       '';
  
        serviceConfig = {
          ExecStart = "${cfg.package}/bin/unbound -d -c ${stateDir}/unbound.conf";
          ExecStopPost="${pkgs.utillinux}/bin/umount ${stateDir}/dev/random";
  
          ProtectSystem = true;
  