PrintErr(...interface{})

	// IsTerminal returns whether the UI is known to be tied to an
	// interactive terminal (as opposed to being redirected to a file).
	IsTerminal() bool

	// WantBrowser indicates whether browser should be opened with the -http option.
	WantBrowser() bool

	// SetAutoComplete instructs the UI to call complete(cmd) to obtain
	// the auto-completion of cmd, if the UI supports auto-completion at all.

	PrintErr(...interface{})

	// IsTerminal returns whether the UI is known to be tied to an
	// interactive terminal (as opposed to being redirected to a file).
	IsTerminal() bool

	// WantBrowser indicates whether a browser should be opened with the -http option.
	WantBrowser() bool

	// SetAutoComplete instructs the UI to call complete(cmd) to obtain
	// the auto-completion of cmd, if the UI supports auto-completion at all.