anchor.diff: -{ config, pkgs ,lib ,... }:
  +{ config, pkgs, lib, ... }:
   
   with lib;
   
  
positive.code:     let
        cfg = config.xdg.portal;
        packages = [ pkgs.xdg-desktop-portal ] ++ cfg.extraPortals;
        joinedPortals = pkgs.symlinkJoin {
          name = "xdg-portals";
          paths = cfg.extraPortals;
        };
  
      in mkIf cfg.enable {
  
        assertions = [
          { assertion = (cfg.gtkUsePortal -> cfg.extraPortals != []);
            message = "Setting xdg.portal.gtkUsePortal to true requires a portal implementation in xdg.portal.extraPortals such as xdg-desktop-portal-gtk or xdg-desktop-portal-kde.";
          }
        ];
  
        services.dbus.packages  = packages;
        systemd.packages = packages;
  
        environment.sessionVariables = {
          GTK_USE_PORTAL = mkIf cfg.gtkUsePortal "1";
          XDG_DESKTOP_PORTAL_DIR = "${joinedPortals}/share/xdg-desktop-portal/portals";
        };
      };
  }
  
negative.code: 
    options.xdg.portal = {
      enable =
        mkEnableOption "<link xlink:href='https://github.com/flatpak/xdg-desktop-portal'>xdg desktop integration</link>" // {
          default = false;
        };
  
      extraPortals = mkOption {
        type = types.listOf types.package;
        default = [ ];
        description = ''
          List of additional portals to add to path. Portals allow interaction
          with system, like choosing files or taking screenshots. At minimum,
  