ranges/ranges.go
func (it *inclusiveRangeIt) IsDone() bool {
	if it.pos >= it.ptr.Len() {
		return true
	}
	return false
}
func (it *inclusiveRangeIt) IsDone() bool {
	if it.pos >= it.ptr.Len() {
		return true
	}
	return false
}
// IsDone returns false while the iterator is valid
// and can produce another value, via a call to Next()