rbt

type RBTree interface {
	Add(val Value) (ok bool)
	Delete(val Value) (ok bool)
	Exists(val Value) (ok bool)
	Size() uint32
	Empty() bool
	Maximum() []Value
	Minimum() []Value
	PopMaximum() []Value
	PopMinimum() []Value
	Asc() []Value
	Desc() []Value
	String() string
	ToJSON() []byte
}

type Value interface {
	ID() string
	String() string
	Compare(Value) stringutil.Diff
	ToJSON() []byte
}