anchor.diff:  
     nixpkgs.config.allowUnfreePredicate = pkg: builtins.elem (lib.getName pkg) [
       "dropbox"
  +    "nvidia-settings"
  +    "nvidia-x11"
       "skypeforlinux"
       "slack"
       "spotify"
  
positive.code:     ${pkgs.xorg.xset}/bin/xset r rate 200 50
      ${pkgs.xorg.xmodmap} ~/.Xmodmap
      '';
    };
    services.autorandr = {
      enable = true;
  
negative.code: 
    services.xserver = {
      enable = true;
      videoDrivers = [ "nvidia" ];
      windowManager.xmonad = {
        enable = true;
        enableContribAndExtras = true;
  