code: func (container *Container) UnmountVolumes(volumeEventLog func(name, action string, attributes map[string]string)) error {
  	var errors []string
  	for _, volumeMount := range container.MountPoints {
  		if volumeMount.Volume == nil {
  			continue
  		}
  
  		if err := volumeMount.Cleanup(); err != nil {
  			errors = append(errors, err.Error())
  			continue
  		}
  
  		attributes := map[string]string{
  			"driver":    volumeMount.Volume.DriverName(),
  			"container": container.ID,
  		}
  		volumeEventLog(volumeMount.Volume.Name(), "unmount", attributes)
  	}
  	if len(errors) > 0 {
  		return fmt.Errorf("error while unmounting volumes for container %s: %s", container.ID, strings.Join(errors, "; "))
  	}
  	return nil
  }
docs: // UnmountVolumes unmounts all volumes