t.Error("second Set() returned true")
	}
	goGetAndExpect(t, wr, gots, aval)
	cancel()
	time.Sleep(time.Second) // give it a chance to misbehave
	goGetAndExpect(t, wr, gots, aval)
}

func TestWriteOnceCancel(t *testing.T) {
	oldTime := time.Now()
	cval := &oldTime
	ctx, cancel := context.WithCancel(context.Background())
	wr := NewWriteOnce(nil, ctx, cval)
	gots := make(chan interface{})