This was the code that was given to us. This is in Python

class LinkedList:
class Node:
def __init__(self, val, prior=None, next=None):
self. val = val
self. prior = prior
self. next = next

def __init__(self):
self. head = LinkedList. Node(None)
self. head. prior = self. head. next = self. head
self. count = 0
self. cursor = None
self. cursor_idx = -1

def append(self, val):
n = LinkedList. Node(val, prior=self. head. prior, next=self. head)
self. head. prior. next = self. head. prior = n
self. count += 1

def set_cursor(self, idx):
assert idx < self. count
self. cursor = self. head. next
for _ in range(idx):
self. cursor = self. cursor. next
self. cursor_idx = idx

### don't modify any code above this line! ###

def del_after_cursor(self):
assert self. cursor