code: func (devices *DeviceSet) setupVerifyBaseImageUUIDFS(baseInfo *devInfo) error {
  	// If BaseDeviceUUID is nil (upgrade case), save it and return success.
  	if devices.BaseDeviceUUID == "" {
  		if err := devices.saveBaseDeviceUUID(baseInfo); err != nil {
  			return fmt.Errorf("devmapper: Could not query and save base device UUID:%v", err)
  		}
  		return nil
  	}
  
  	if err := devices.verifyBaseDeviceUUIDFS(baseInfo); err != nil {
  		return fmt.Errorf("devmapper: Base Device UUID and Filesystem verification failed: %v", err)
  	}
  
  	return nil
  }
docs: // Base image is initialized properly. Either save UUID for first time (for
  // upgrade case or verify UUID.