class_docstr: Base class for sessions based on signed cookies.
  
  This session backend will set the :attr:`modified` and
  :attr:`accessed` attributes. It cannot reliably track whether a
  session is new (vs. empty), so :attr:`new` remains hard coded to
  ``False``.
code: def __getitem__(self, key: str) -> t.Any:
      self.accessed = True
      return super().__getitem__(key)
  
imports: from __future__ import annotations
  import hashlib
  import typing
  from collections.abc import MutableMapping
  from datetime import datetime
  from datetime import timezone
  from itsdangerous import BadSignature
  from itsdangerous import URLSafeTimedSerializer
  from werkzeug.datastructures import CallbackDict
  from .json.tag import TaggedJSONSerializer
label_desc: Use image node_id 2 for calling the SecureCookieSession obj's underlying member method code with example usage: obj.__getitem__(key) and returns: super