func (s *Skiplist) FreeNode(n *Node, sts *Stats) {
	s.freeNode(n)
	sts.AddInt64(&sts.nodeFrees, 1)
}
func (s *Skiplist) FreeNode(n *Node, sts *Stats) {
	s.freeNode(n)
	sts.AddInt64(&sts.nodeFrees, 1)
}
// FreeNode deallocates the skiplist node memory