query.go
func (iter Enumerator) All(p Predicate) bool {
	for entry := range iter {
		if !p(entry) {
			return false
		}
	}
	return true
}
func (iter Enumerator) All(p Predicate) bool {
	for entry := range iter {
		if !p(entry) {
			return false
		}
	}
	return true
}
// All tests whether or not all items present meet a criteria.