code: func (r Metric_Tracking_Object) GetBackboneBandwidthGraph(graphTitle *string) (resp datatypes.Container_Bandwidth_GraphOutputs, err error) {
  	params := []interface{}{
  		graphTitle,
  	}
  	err = r.Session.DoRequest("SoftLayer_Metric_Tracking_Object", "getBackboneBandwidthGraph", params, &r.Options, &resp)
  	return
  }
docs: // Retrieve a PNG image of the last 24 hours of bandwidth usage of one of SoftLayer's network backbones.