gist 2 https://medium.com/@francesc/two-ways-of-merging-n-channels-in-go-43c0b57cd1de

main.go

func main() {
	a := asChan(0, 1, 2, 3, 4, 5, 6, 7, 8, 9)
	b := asChan(10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
	c := asChan(20, 21, 22, 23, 24, 25, 26, 27, 28, 29)
	for v := range merge(a, b, c) {
		fmt.Println(v)
	}
}