Write a method size that returns the total number of nodes in the tree. For example, the following tree has a size of 8:

 +---+ | 6 | ___ +---+ ___ / \ +---+ +---+ | 3 | | 2 | +---+ +---+ / \ / \ +---+ +---+ +---+ +---+ | 1 | | 4 | | 6 | | 4 | +---+ +---+ +---+ +---+ \ +---+ | 0 | +---+ 

Assume that you are adding this method to the IntTree class as defined below:

public class IntTree{

private IntTreeNode overallRoot; //null for an empty tree

.........

}