From b0d975e21619b6eb1dbcf24a5ed68629298bfdce Mon Sep 17 00:00:00 2001
From: Erik Johnston <erik@matrix.org>
Date: Fri, 9 Jun 2017 16:25:42 +0100
Subject: [PATCH] Comments

---
 synapse/storage/state.py | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/synapse/storage/state.py b/synapse/storage/state.py
index 0bea7374f7..24503cd5aa 100644
--- a/synapse/storage/state.py
+++ b/synapse/storage/state.py
@@ -31,6 +31,9 @@ MAX_STATE_DELTA_HOPS = 100
 
 
 class _GetStateGroupDelta(namedtuple("_GetStateGroupDelta", ("prev_group", "delta_ids"))):
+    """Return type of get_state_group_delta that implements __len__, which lets
+    us use the itrable flag when caching
+    """
     __slots__ = []
 
     def __len__(self):