// Print random int63 number from "mt19937_64".
// Reset random number generator if "i" is 13.
func PrintInt63(i int, mt *rand.Rand, ch chan bool) {
	t := rand.Int() % 1000
	time.Sleep(time.Duration(t))

	if 13 == i {
		mt.Seed(12345)
		fmt.Printf("13 : (reset) \n")
	} else {
		fmt.Printf("%2d : %d \n", i, mt.Int63())
	}

	ch <- true
}