trie.go
func newPrefixTree(version rnet.IPVersion) Ranger {
	_, rootNet, _ := net.ParseCIDR("0.0.0.0/0")
	if version == rnet.IPv6 {
		_, rootNet, _ = net.ParseCIDR("0::0/0")
	}
	return &prefixTrie{
		children:       make([]*prefixTrie, 2, 2),
		numBitsSkipped: 0,
		numBitsHandled: 1,
		network:        rnet.NewNetwork(*rootNet),
	}
}
func newPrefixTree(version rnet.IPVersion) Ranger {
	_, rootNet, _ := net.ParseCIDR("0.0.0.0/0")
	if version == rnet.IPv6 {
		_, rootNet, _ = net.ParseCIDR("0::0/0")
	}
	return &prefixTrie{
		children:       make([]*prefixTrie, 2, 2),
		numBitsSkipped: 0,
		numBitsHandled: 1,
		network:        rnet.NewNetwork(*rootNet),
	}
}
// newPrefixTree creates a new prefixTrie.