anchor.diff:          networkmanager_openvpn
           networkmanager_vpnc
           networkmanager_openconnect
  +        networkmanager_pptp
           ];
   
       users.extraGroups = singleton {
  
positive.code:       { source = "${networkmanager_openconnect}/etc/NetworkManager/VPN/nm-openconnect-service.name";
          target = "NetworkManager/VPN/nm-openconnect-service.name";
        }
      ] ++ pkgs.lib.optional (cfg.appendNameservers == [] || cfg.insertNameservers == [])
             { source = overrideNameserversScript;
               target = "NetworkManager/dispatcher.d/02overridedns";
  
negative.code:         networkmanager_openvpn
          networkmanager_vpnc
          networkmanager_openconnect
          networkmanager_pptp
          ];
  
      services.udev.packages = cfg.packages;
  