uratrie

type Node struct {
	// segment => *regexp.Regexp
	Regexps map[string]*regexp.Regexp
	// segment => *Node
	Childrens map[string]*Node
	// userIDs
	Container *roaring.Bitmap
	// because it is a different branch, it can only be all single or all multiple.
	// segment index => wildcard key => path key
	Wildcards map[int]map[string]string
	// whether leaf node
	Leaf bool
}