From c0669289156b4cfc0aea282377a181f73ff81e06 Mon Sep 17 00:00:00 2001
From: Erik Johnston <erik@matrix.org>
Date: Tue, 11 Aug 2020 22:01:12 +0100
Subject: [PATCH] Add comment explaining cast

---
 synapse/server.py | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/synapse/server.py b/synapse/server.py
index c78eb2fe4..9055b97ac 100644
--- a/synapse/server.py
+++ b/synapse/server.py
@@ -163,6 +163,8 @@ def cache_in_self(builder: T) -> T:
 
         return dep
 
+    # We cast here as we need to tell mypy that `_get` has the same signature as
+    # `builder`.
     return cast(T, _get)