code: func (r *RefErrUnsupportedDetail) Lines() []string {
  	lines := []string{
  		r.Ref.String(),
  		strings.Repeat("^", len(r.Ref[:r.Pos+1].String())),
  		fmt.Sprintf("have: %v", r.Have),
  	}
  	return lines
  }
docs: // Lines returns the string representation of the detail.