anchor.diff:        enable = mkOption {
           default = false;
           description = "Enable Gnome 3 desktop manager.";
  -      };
  -
  -      sessionPath = mkOption {
  -        default = [];
  -        example = literalExample "[ pkgs.gnome3.gpaste ]";
  -        description = "Additional list of packages to be added to the session search path.
  -                       Useful for gnome shell extensions or gsettings-conditionated autostart.";
  -        apply = list: list ++ [ pkgs.gnome3.gnome-shell pkgs.gnome3.gnome-shell-extensions ];
         };
   
         extraGSettingsOverrides = mkOption {
  
positive.code:     environment.variables.GIO_EXTRA_MODULES = [ "${lib.getLib pkgs.gnome3.dconf}/lib/gio/modules"
                                                  "${pkgs.gnome3.glib-networking.out}/lib/gio/modules"
                                                  "${pkgs.gnome3.gvfs}/lib/gio/modules" ];
      environment.systemPackages = pkgs.gnome3.corePackages ++ cfg.sessionPath
        ++ (removePackagesByName pkgs.gnome3.optionalPackages config.environment.gnome3.excludePackages) ++ [
        pkgs.xdg-user-dirs # Update user dirs as described in http://freedesktop.org/wiki/Software/xdg-user-dirs/
      ];
  
negative.code: 
            export XDG_MENU_PREFIX=gnome-
  
            # Override default mimeapps
            export XDG_DATA_DIRS=$XDG_DATA_DIRS''${XDG_DATA_DIRS:+:}${mimeAppsList}/share
  
  