Write a function that takes as input a general tree and returns the number of nodes in that tree. Write your function to use the GenTree and GTNode ADTs of Figure 6.2.

/** General tree ADT */ interface GenTree { public void clear(); public GTNode root (); // Clear the tree // Return the root // Make the tree have a new root, give first child and sib public void newroot (E value, GTNode first, GTNode sib); public void newleftchild (E value); // Add left child } Figure 6.2 The general tree node and general tree classes.