code: func NewCmd(cmd *exec.Cmd) *Cmd {
  	c := &Cmd{
  		Cmd:     cmd,
  		stopped: make(chan struct{}, 1),
  	}
  	c.stoppingValue.Store(false)
  	c.Stdout = os.Stdout
  	c.Stderr = os.Stderr
  	return c
  }
docs: // NewCmd returns a new instance of Cmd that wraps cmd.