Add type stub files

aiohttp_security/cookies_identity.pyi

@@ -0,0 +1,12 @@
+from .abc import AbstractIdentityPolicy, Identity
+from typing import Any, Union
+import aiohttp.web
+
+class sentinel: ...
+
+
+class CookiesIdentityPolicy(AbstractIdentityPolicy):
+    def __init__(self) -> None: ...
+    async def identify(self, request: aiohttp.web.Request) -> Identity: ...
+    async def remember(self, request: aiohttp.web.Request, response: aiohttp.web.StreamResponse, identity: Identity, max_age: Union[sentinel, int]=..., **kwargs: Any) -> None: ...
+    async def forget(self, request: aiohttp.web.Request, response: aiohttp.web.StreamResponse) -> None: ...