From bab97cf319848ae6cdea4c4b3c5e5c71f3b5b6fc Mon Sep 17 00:00:00 2001
From: Itamar Turner-Trauring <itamar@pythonspeed.com>
Date: Thu, 19 Oct 2023 11:12:44 -0400
Subject: [PATCH] Document constraints.

---
 src/allmydata/storage/http_client.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/allmydata/storage/http_client.py b/src/allmydata/storage/http_client.py
index 7f6fecb98..a98b097dd 100644
--- a/src/allmydata/storage/http_client.py
+++ b/src/allmydata/storage/http_client.py
@@ -474,7 +474,8 @@ class StorageClient(object):
         into corresponding HTTP headers.
 
         If ``message_to_serialize`` is set, it will be serialized (by default
-        with CBOR) and set as the request body.
+        with CBOR) and set as the request body.  It should not be mutated
+        during execution of this function!
 
         Default timeout is 60 seconds.
         """