protected function insertNode($destLeft, $destRight, $destRoot=null)
    {
        $this->setLeftValue($destLeft);
        $this->setRightValue($destRight);
        if($this->hasManyRoots())
        {
            $this->setRootValue($destRoot);
        }
        $this->getManager()->getEntityManager()->persist($this->getNode());
    }