query.go
func (iter Enumerator) ElementAt(n uint) interface{} {
	for i := uint(0); i < n; i++ {
		<-iter
	}
	return <-iter
}
func (iter Enumerator) ElementAt(n uint) interface{} {
	for i := uint(0); i < n; i++ {
		<-iter
	}
	return <-iter
}
// ElementAt retreives an item at a particular position in an Enumerator.