code: func (p *terminalPrompter) PromptPassword(prompt string) (passwd string, err error) {
  	if p.supported {
  		p.rawMode.ApplyMode()
  		defer p.normalMode.ApplyMode()
  		return p.State.PasswordPrompt(prompt)
  	}
  	if !p.warned {
  		fmt.Println("!! Unsupported terminal, password will be echoed.")
  		p.warned = true
  	}
  	// Just as in Prompt, handle printing the prompt here instead of relying on liner.
  	fmt.Print(prompt)
  	passwd, err = p.State.Prompt("")
  	fmt.Println()
  	return passwd, err
  }
docs: // PromptPassword displays the given prompt to the user and requests some textual
  // data to be entered, but one which must not be echoed out into the terminal.
  // The method returns the input provided by the user.