Clarify list/set/dict/tuple comprehensions and enforce via flake8 (#6957)

* commit '509e381af':
  Clarify list/set/dict/tuple comprehensions and enforce via flake8 (#6957)
  changelog
  Increase MAX_EVENTS_BEHIND for replication clients

1 files changed, 1 insertions, 1 deletions

diff --git a/synapse/storage/_base.py b/synapse/storage/_base.py

index da3b99f93d..13de5f1f62 100644
--- a/synapse/storage/_base.py
+++ b/synapse/storage/_base.py
@@ -56,7 +56,7 @@ class SQLBaseStore(metaclass=ABCMeta):
             members_changed (iterable[str]): The user_ids of members that have
                 changed
         """
-        for host in set(get_domain_from_id(u) for u in members_changed):
+        for host in {get_domain_from_id(u) for u in members_changed}:
             self._attempt_to_invalidate_cache("is_host_joined", (room_id, host))
             self._attempt_to_invalidate_cache("was_host_joined", (room_id, host))