Fix rotate_left
@@ -230,7 +230,7 @@ impl<K,V> Node<K,V> where K:Ord+Debug {
let mut dnode = dtree.as_mut().unwrap();
let ctree = dnode.left.take();
let etree = dnode.right.take();
- let atree = self.right.take();
+ let atree = self.left.take();
// D becomes B and B becomes D
swap(&mut self.key, &mut dnode.key);
