1. Consider the code below, is this a pre- post- or in- order
     traversal of a binary tree?

     ,----
     | foo(Node n){
     |   foo(n.left);
     |   foo(n.right);
     |   process(n.data);
     | }
     `----
  2. What is the in-order traversal of the following tree?

     ,----
     |      A
     |    /   \
     |   O     V 
     |  / \   /
     | G   N Y
     `----

  3. Complete the recursive method to find an element in a binary tree
     containing integerss?

      ,----
      | public boolean find(int element){
      |   return findFrom(root,item);
      | }
      | 
      | public boolean findFrom(Node n, int element){
      |    if (n == null) return false;
      |    else if (n.data == data) return true;
      |    //TODO: complete me!
      | 
      | }
      `----