code: func NewDiffVersion(name string) (*DiffVersion, error) {
  	dir, err := CreateDirectory(name)
  	if err != nil {
  		return nil, err
  	}
  	return &DiffVersion{
  		Dir:  dir,
  		Name: name,
  	}, nil
  }
docs: // NewDiffVersion creates a new DiffVersion with the named version.