What are the errors is my code?
Output is coming same as the input.
I can’t find any errors.

I was expecting a perfect answer.
I trying to do this question through recursion only.

Code————–

class Solution {
    public ListNode swapPairs(ListNode head) {
        if(head==null || head.next!=null){
            return head;
        }
        ListNode node1=head;
        ListNode node2=head.next;
        head=recursion(node1,node2);
        return head;
    }
    public ListNode recursion(ListNode node1,ListNode node2){
        if(node2==null){
            return node2;
        }
        if(node2.next==null){
            node2.next=node1;
            node1.next=null;
            return node2;
        }
        ListNode head=recursion(node2.next,node2.next.next);
        node2.next=node1;
        node1.next=head;
        return node2;   
    }
}