Question 2 [6 + 8 Marks] (A) [6 Marks] Consider the generic class called ArrayStack as discussed in the lectures, having following data fields: private E( ) theData; // array to store stack elements private int topOfStack = -1; // Index to top of stack, initially empty stack. private static final int INITIAL_CAPACITY = 10; Write a method called replaceTop to be included in this class ArrayStack. If stack is not empty, then the method replaces the top element of the stack by parameter item and returns the old value at the top. If the stack is empty, return null. Do not call any other method of the class ArrayStack in your method. Example: top stack (Before method call): 5, 20, 10, 50, 15, 30 item: 7 top stack (After method call): 7, 20, 10, 50, 15, 30 Method will return 5. Method Heading: public E replaceTop (E item)