Problem Sheet #2 1. Given the following stack class declaration, write the following methods using an array-based implementation: public void push (E data) public boolean isEmpty Note: There is no currentsize variable here. Do we need it? . public E pop 0 . public boolean isFull class Stack private int head: private int maxSize: private E I stack: public Stack (int size) maxSize size: head =-1 ; stack - (EI) new Object [maxsizel: publie void push (E data) public E pop) ( public boolean isFull public boolean isEmptyo