var dummy = make(chan bool)

type SSChan chan int

func (c SSChan) Send(x int) {
	select {
	case c <- x:
	case <-dummy:
	}
}

func (c SSChan) Nbsend(x int) bool {
	select {
	default:
		return false
	case <-dummy:
	case c <- x:
		return true
	}
	panic("nbsend")
}

func (c SSChan) Recv() int {
	select {
	case <-dummy:
	case x := <-c: