Function langForFunc

worker/task.go:1864–1870

We allow atmost one lang in functions. We can inline in 1.9.

(langs []string)

// We allow atmost one lang in functions. We can inline in 1.9.
func langForFunc(langs []string) string {
	x.AssertTrue(len(langs) <= 1)
	if len(langs) == 0 {
		return ""
	}
	return langs[0]
}

func checkUidZero(uids []uint64) bool {
	for _, uid := range uids {