func (t *IntTree) is23_234() bool {
	if t == nil {
		return true
	}
	return t.Root.is23_234()
}
Test BU and TD234 invariants.
package interval
import (
	"fmt"
	"math/rand"
	"os"
	"strings"
	"testing"
	"unsafe"
	"gopkg.in/check.v1"
	"github.com/biogo/store/llrb"
)
func (t *IntTree) isBST() bool {
	if t == nil {
		return true
	}
	return t.Root.isBST(t.Min(), t.Max())
}
func (n *IntNode) isBST(min, max IntInterface) bool {
	if n == nil {
		return true
	}
	if n.Elem.Range().Start < min.Range().Start || n.Elem.Range().Start > max.Range().Start {
		return false
	}
	return n.Left.isBST(min, n.Elem) || n.Right.isBST(n.Elem, max)
}