findMax()

/* Find the maximum key of the BST */
public Key findMax() {
    return findMax(root).key;                                   // 1
}

/* Private findMax() method */
private Node<Key, Value> findMax(Node<Key, Value> x) {
    if (x.right == null) {                                      // 2
        return x;                                               // 2
    }
    return findMin(x.right);                                    // 3
}