from __future__ import annotations
from dataclasses import dataclass
from typing import Any, Optional


@dataclass
class _Node:
    """A node in a linked list.

    Note that this is considered a "private class", one which is only meant
    to be used in this module by the LinkedList class, but not by client code.

    Instance Attributes:
      - item: The data stored in this node.
      - next: The next node in the list, if any.
    """
    item: Any
    next: Optional[_Node] = None  # By default, this node does not link to any other node


class LinkedList:
    """A linked list implementation of the List ADT.
    """
    # Private Instance Attributes:
    #   - _first: The first node in this linked list, or None if this list is empty.
    _first: Optional[_Node]

    def __init__(self) -> None:
        """Initialize an empty linked list.
        """
        self._first = None

    def print_items(self) -> None:
        curr = self._first
        while curr is not None:
            print(curr.item)
            curr = curr.next

    def __getitem__(self, i: int) -> Any:
        return 5  # Check Notion
# linky._first = _Node('a', _Node('b', _Node('c')))