Exercise 4: Recursion and Binary Trees Add a recursive function getHeight to the BinarySearchTree class in Exercise 1 that returns the height of the tree. Create a Main class to test it. Exercise 5: Using Properties of BSTs Add methods preorderDisplay and postorderDisplay to the BinarySearchTree class in Exercise 1 to print the items in the BST listed in preorder and postorder, respectively. Create a Main class to test them.