anchor.diff:  
   let
     cfg = config.networking.connman;
  +  configFile = pkgs.writeText "connman.conf" ''
  +    [General]
  +    NetworkInterfaceBlacklist=${concatStringsSep "," cfg.networkInterfaceBlacklist}
   
  +    ${cfg.extraConfig}
  +  '';
   in {
   
     ###### interface
  
positive.code:         default = false;
          description = ''
            Whether to use ConnMan for managing your network connections.
          '';
        };
  
  
negative.code:         Type = "dbus";
          BusName = "net.connman";
          Restart = "on-failure";
          ExecStart = "${pkgs.connman}/sbin/connmand --config=${configFile} --nodaemon";
          StandardOutput = "null";
        };
      };
  