anchor.diff:  
         if (throttle > 0)
           args..add("--throttle")..add(throttle.toString());
  +
  +      if ()
       }
   
       _log.fine(args.join(" "));
  
positive.code:     return runDuck(args);
    }
  
    Future download(String remotePath, String localPath, {LoadOptions handleExisting}) async {
      var args = [
        "--download", _url.absolute(remotePath), path.absolute(localPath)
      ];
  
negative.code:   ///Throttle bandwidth <bytes per second>
    int throttle;
  
    ///Preserve permissions and modification date for transferred files
    bool preservePermissionsAndModDate;
  
    //TODO: Support password authentication as secure as possible
  
    DuckProcess(this.remoteRoot,
        {
        this.user: "",
        this.externalEditor: "",
        this.identityFile: "",
        this.password: "",
        this.quiet: true,
        this.verbose: false,
        this.assume_yes: true,
        this.preservePermissionsAndModDate: null,
        this.throttle: 0
        }) {
      //TODO: add unit support for throttling (KB, MB, GB)
      //
  
  