code: private void linkInPlace(Node<K, V> orphan, Node<K, V> n) {
          // link orphan at node's position
          orphan.y_s = n.y_s;
          if (n.y_s != null) {
              n.y_s.o_s = orphan;
          }
          orphan.o_s = n.o_s;
          if (n.o_s != null) {
              if (n.o_s.o_c == n) { // node is the oldest :(
                  n.o_s.o_c = orphan;
              } else { // node has an older sibling!
                  n.o_s.y_s = orphan;
              }
          }
          n.o_s = null;
          n.y_s = null;
      }
docs: Put an orphan node into the position of another node. The other node
  becomes an orphan.
  
  @param orphan
  the orphan node
  @param n
  the node which will become an orphan