query.go
func Take(subject Enumerable, n uint) Enumerable {
	return taker{
		original: subject,
		n:        n,
	}
}
func Take(subject Enumerable, n uint) Enumerable {
	return taker{
		original: subject,
		n:        n,
	}
}
// Take retreives just the first `n` elements from an Enumerable.