finish the implementation of this LinkedList thanks

def setitem_(self, index: int, item: Any) -> None: "Store item at position in this list. Raise IndexError if index >= len(self). (0, 10 # >>> Lst - Linkedlist([1, 2, 3]) # >>> Ist[@] = 100 # Equivalent to lst._setitem # >>> Ist[1] = 200 # >>> Ist[2] = 300 # >>> str(Lst) # '[100 -> 200 -> 300] curr = self._first count = 0