code: func (r Hardware_Server) GetBandwidthForDateRange(startDate *datatypes.Time, endDate *datatypes.Time) (resp []datatypes.Metric_Tracking_Object_Data, err error) {
  	params := []interface{}{
  		startDate,
  		endDate,
  	}
  	err = r.Session.DoRequest("SoftLayer_Hardware_Server", "getBandwidthForDateRange", params, &r.Options, &resp)
  	return
  }
docs: // Retrieve a collection of bandwidth data from an individual public or private network tracking object. Data is ideal if you with to employ your own traffic storage and graphing systems.