Function clamp

utils.go:9–19

(offset, limit, length int)

)

func clamp(offset, limit, length int) (int, int) {
	start := length
	if offset < length {
		start = offset
	}
	end := length
	if limit < length-start {
		end = start + limit
	}
	return start, end
}

func contains(arr []string, el string) bool {
	for _, item := range arr {