code: func getAvailableSCSIController(scsiControllers []*types.VirtualController) *types.VirtualController {
  	// get SCSI controller which has space for adding more devices
  	for _, controller := range scsiControllers {
  		if len(controller.Device) < SCSIControllerDeviceLimit {
  			return controller
  		}
  	}
  	return nil
  }
docs: // getAvailableSCSIController gets available SCSI Controller from list of given controllers, which has less than 15 disk devices.