code: func (r Location_Datacenter) GetStatisticsGraphImage() (resp []byte, err error) {
  	err = r.Session.DoRequest("SoftLayer_Location_Datacenter", "getStatisticsGraphImage", nil, &r.Options, &resp)
  	return
  }
docs: // Retrieve a graph of a SoftLayer datacenter's last 48 hours of network activity. Statistics graphs show traffic outbound from a datacenter on top and inbound traffic on the bottom followed by a legend of the network services tracked in the graph. getStatisticsGraphImage returns a PNG image of variable width and height depending on the number of services reported in the image.