From 27b1b4a2c958b04f37732d19f163dcfab12ad0a7 Mon Sep 17 00:00:00 2001
From: Erik Johnston <erik@matrix.org>
Date: Thu, 30 Mar 2017 17:50:31 +0100
Subject: [PATCH] Speed up copy_and_replace

---
 synapse/types.py | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/synapse/types.py b/synapse/types.py
index 9666f9d73f..c87ed813b9 100644
--- a/synapse/types.py
+++ b/synapse/types.py
@@ -216,9 +216,7 @@ class StreamToken(
             return self
 
     def copy_and_replace(self, key, new_value):
-        d = self._asdict()
-        d[key] = new_value
-        return StreamToken(**d)
+        return self._replace(**{key: new_value})
 
 
 StreamToken.START = StreamToken(