code: func (ui *PrefixUI) Error(message string) {
  	if ui.ErrorPrefix == " " { //Lets keep the space if they want one
  		message = ui.ErrorPrefix + message
  	} else if ui.ErrorPrefix != "" {
  		message = ui.ErrorPrefix + " " + message
  	}
  	ui.UI.Error(message)
  }
docs: // Error call UI.Error to write.
  // ErrorPrefix is used to prefix the message.