trie.go
func (p *prefixTrie) Contains(ip net.IP) (bool, error) {
	nn := rnet.NewNetworkNumber(ip)
	if nn == nil {
		return false, ErrInvalidNetworkNumberInput
	}
	return p.contains(nn)
}
func (p *prefixTrie) Contains(ip net.IP) (bool, error) {
	nn := rnet.NewNetworkNumber(ip)
	if nn == nil {
		return false, ErrInvalidNetworkNumberInput
	}
	return p.contains(nn)
}
// Contains returns boolean indicating whether given ip is contained in any
// of the inserted networks.