code: func (ui *BasicUI) Error(message string) {
  	if ui.ErrorWriter != nil {
  		fmt.Fprint(ui.ErrorWriter, message)
  		fmt.Fprint(ui.ErrorWriter, "\n")
  	} else {
  		fmt.Fprint(ui.Writer, message)
  		fmt.Fprint(ui.Writer, "\n")
  	}
  }
docs: // Error writes message to ErrorWriter.