anchor.diff:    ###### interface
   
     options = {
  -  
  +
       networking.WLANInterface = mkOption {
         default = "";
         description = "Obsolete. Use <option>networking.wireless.interfaces</option> instead.";
  
positive.code:             exec wpa_supplicant -s -u ${optionalString (cfg.driver != "") "-D${cfg.driver}"} -c ${configFile} $ifaces
            '';
        };
    
      powerManagement.resumeCommands =
        ''
          ${config.system.build.upstart}/sbin/restart wpa_supplicant
        '';
  
      assertions = [{ assertion = !cfg.userControlled.enable || cfg.interfaces != []; 
                      message = "user controlled wpa_supplicant needs explicit networking.wireless.interfaces";}];
  
    };
  
negative.code: 
  
    ###### implementation
  
    config = mkIf cfg.enable {
  
      environment.systemPackages =  [ pkgs.wpa_supplicant ];
  
      services.dbus.packages = [ pkgs.wpa_supplicant ];
  
      jobs.wpa_supplicant =
        { startOn = "started network-interfaces";
          stopOn = "stopping network-interfaces";
  
  