trie.go
func (p *prefixTrie) ContainingNetworks(ip net.IP) ([]RangerEntry, error) {
	nn := rnet.NewNetworkNumber(ip)
	if nn == nil {
		return nil, ErrInvalidNetworkNumberInput
	}
	return p.containingNetworks(nn)
}
func (p *prefixTrie) ContainingNetworks(ip net.IP) ([]RangerEntry, error) {
	nn := rnet.NewNetworkNumber(ip)
	if nn == nil {
		return nil, ErrInvalidNetworkNumberInput
	}
	return p.containingNetworks(nn)
}
// ContainingNetworks returns the list of RangerEntry(s) the given ip is
// contained in in ascending prefix order.