anchor.diff:      '';
   
     flashbackEnabled = cfg.flashback.enableMetacity || length cfg.flashback.customSessions > 0;
  +
  +  notExcluded = pkg: mkDefault (!(lib.elem pkg config.environment.gnome3.excludePackages));
   
   in
   
  
positive.code:       environment.pathsToLink = [
          "/share/nautilus-python/extensions"
        ];
      })
  
      # Enable default program modules
      # Since some of these have a corresponding package, we only
      # enable that program module if the package hasn't been excluded
      # through `environment.gnome3.excludePackages`
      (
      let
        notExcluded = pkg: mkDefault (!(lib.elem pkg config.environment.gnome3.excludePackages));
      in
      with pkgs.gnome3;
      {
        programs.evince.enable = notExcluded evince;
        programs.file-roller.enable = notExcluded file-roller;
        programs.geary.enable = notExcluded geary;
        programs.gnome-disks.enable = notExcluded gnome-disk-utility;
        programs.gnome-terminal.enable = notExcluded gnome-terminal;
        programs.seahorse.enable = notExcluded seahorse;
        services.gnome3.sushi.enable = notExcluded sushi;
      })
  
      (mkIf serviceCfg.games.enable {
  
negative.code:         /* gnome-boxes */
        ] config.environment.gnome3.excludePackages);
  
        # Enable default program modules
        # Since some of these have a corresponding package, we only
        # enable that program module if the package hasn't been excluded
        # through `environment.gnome3.excludePackages`
        programs.evince.enable = notExcluded pkgs.gnome3.evince;
        programs.file-roller.enable = notExcluded pkgs.gnome3.file-roller;
        programs.geary.enable = notExcluded pkgs.gnome3.geary;
        programs.gnome-disks.enable = notExcluded pkgs.gnome3.gnome-disk-utility;
        programs.gnome-terminal.enable = notExcluded pkgs.gnome3.gnome-terminal;
        programs.seahorse.enable = notExcluded pkgs.gnome3.seahorse;
        services.gnome3.sushi.enable = notExcluded pkgs.gnome3.sushi;
  
        # Let nautilus find extensions
        # TODO: Create nautilus-with-extensions package
        environment.sessionVariables.NAUTILUS_EXTENSION_DIR = "${config.system.path}/lib/nautilus/extensions-3.0";
  