code: func (r Virtual_Disk_Image) GetBillingItem() (resp datatypes.Billing_Item_Virtual_Disk_Image, err error) {
  	err = r.Session.DoRequest("SoftLayer_Virtual_Disk_Image", "getBillingItem", nil, &r.Options, &resp)
  	return
  }
docs: // Retrieve The billing item for a virtual disk image.