simple question about function

public class test {
	private Node head;
	
	private class Node{
		int p;
		Node next;
		
		public Node(int p, Node next) {
			this.p = p;
			this.next = next;
		}
	}
	
	public void set() {
		set(head);
	}
	
	private void set(Node p) {
		p = new Node(1, null);
	}
	
	public boolean isEmpty() {
		return head == null;
	}
	
	public static void main(String[] args) {
		test a = new test();
		a.set();
		System.out.println(a.isEmpty());
	}
}