Fix Notification factory return type & import layout.

tildes/tildes/models/comment/comment_notification.py

@@ -1,8 +1,8 @@
 """Contains the CommentNotification class."""
 
 from datetime import datetime
-
 from typing import Any, Sequence, Tuple
+
 from pyramid.security import Allow, DENY_ALL
 from sqlalchemy import Boolean, Column, ForeignKey, Integer, TIMESTAMP
 from sqlalchemy.dialects.postgresql import ENUM

tildes/tildes/resources/comment.py

@@ -29,7 +29,7 @@ def comment_by_id36(request: Request, comment_id36: str) -> Comment:
 def notification_by_comment_id36(
         request: Request,
         comment_id36: str
-) -> Comment:
+) -> CommentNotification:
     """Get a comment notification specified by {comment_id36} in the route.
 
     Looks up a comment notification from the request user and a {comment_id36}