code: function update_config(jobName, modifyFunction, customParams, callback) {
        var _doArgs27 = doArgs(arguments, ['string', 'function', ['object', {}], 'function']);
  
        var _doArgs28 = _slicedToArray(_doArgs27, 4);
  
        jobName = _doArgs28[0];
        modifyFunction = _doArgs28[1];
        customParams = _doArgs28[2];
        callback = _doArgs28[3];
  
  
        var self = this;
  
        self.get_config_xml(jobName, customParams, function (error, data) {
          if (error) {
            callback(error, data);
            return;
          }
  
          // Modify the config data
          data = modifyFunction(data);
  
          self.update_job(jobName, data, customParams, callback);
        });
      }
docs: Update a job config xml by passing it through your modifyFunction.