SessionMixin (sessions.py)

Provides session persistence layer.

from __future__ import annotations

import collections.abc as c
import hashlib
import typing as t
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

if t.TYPE_CHECKING:  # pragma: no cover
    import typing_extensions as te

    from .app import Flask
    from .wrappers import Request
    from .wrappers import Response


class SessionMixin(MutableMapping[str, t.Any]):
    """Expands a basic dictionary with session attributes."""

    @property
    def permanent(self) -> bool:
        """This reflects the ``'_permanent'`` key in the dict."""
        return self.

... (truncated -- full source via MCP)