```py class ListNode: def __init__(self, val=0, next=None): self.val = val self.next = next class Solution: def addTwoNumbers(self, l1: Optional[ListNode], l2: Optional[ListNode]) -> Optional[ListNode]: def recursiveLLtraversal(Node): if Node.next == None: return f"{Node.val}," else: return f"{Node.val},{recursiveLLtraversal(Node.next)}," def insertz(oldhead, val): New = ListNode() New.val = val New.next = oldhead return New val1 = recursiveLLtraversal(l1) val2 = recursiveLLtraversal(l2) tot = list(f"{int(val1)}, + {int(val2)},") headval = None for i in range(0,len(tot)): headval = insertz(tot[i], headval) while True: if headval.next == None: False else: print(headval.val) headval = headval.next return headval ``` Getting this error
can you give a test input