Please complete the code

public class SinglyLinkedList> t private static class Node private E value; private Node next; private Node(E value,Node next) this. value value; this.next next; // Instance variable private Node head; // SinglyLinkedList methods / returns true if the list is empty*/ public boolean isEmpty) return head null; public void addfirst(E item) t //this method will be use to populate the list if (item = null) { throw new NullPointerException("Illegal argument"); head new Node(item, head); //The recursive method size returns the number of nodes in the list public int size)t // the public size method calls a private recursive method size starting from head return size(head); private int size(Node p)t //complete this method / /The recursive method get returns the element at position index (first element is at position 0) public E get( int index ) if (index0) return null; else return .....i// make a call to the private recursive method