code: func (v *Volume) String() string {
  	var paths []string
  	if v.Source != "" {
  		paths = []string{v.Source, v.Destination}
  	} else {
  		paths = []string{v.Destination}
  	}
  	if v.AccessMode != "" {
  		paths = append(paths, v.AccessMode)
  	}
  	return strings.Join(paths, ":")
  }
docs: // String implements the Stringer interface.