policy(minor): fix linting

passbook/policy/engine.py

@@ -1,15 +1,15 @@
 """passbook policy engine"""
 from multiprocessing import Pipe
 from multiprocessing.connection import Connection
-from typing import List, Tuple, Dict
+from typing import List, Tuple
 
 from django.core.cache import cache
 from django.http import HttpRequest
 from structlog import get_logger
 
 from passbook.core.models import Policy, User
-from passbook.policy.struct import PolicyRequest, PolicyResult
 from passbook.policy.process import PolicyProcess
+from passbook.policy.struct import PolicyRequest, PolicyResult
 
 LOGGER = get_logger()
 
@@ -17,6 +17,7 @@ def _cache_key(policy, user):
     return f"policy_{policy.pk}#{user.pk}"
 
 class PolicyProcessInfo:
+    """Dataclass to hold all information and communication channels to a process"""
 
     process: PolicyProcess
     connection: Connection