sh.printLock.Lock()
	defer sh.printLock.Unlock()
	sh.printFunc(a...)
}

func (sh *Shell) printLocked(a ...any) {
	sh.printFunc(a...)
}

// WithAction returns a Shell identical to sh, but bound to Action a.
func (sh *Shell) WithAction(a *Action) *Shell {
	sh2 := *sh
	sh2.action = a
	return &sh2
}

// Shell returns a shell for running commands on behalf of Action a.