From 7681cd9a188b1238fa921c60721627ed22fb9e33 Mon Sep 17 00:00:00 2001
From: ArtemIsmagilov <artem.ismagilov.2000@mail.ru>
Date: Wed, 12 Jun 2024 18:30:00 +0400
Subject: [PATCH] change mut arg on None and added checker is None

---
 caldav/davclient.py | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/caldav/davclient.py b/caldav/davclient.py
index 9e85eac..89edc96 100644
--- a/caldav/davclient.py
+++ b/caldav/davclient.py
@@ -618,11 +618,14 @@ def request(
         url: str,
         method: str = "GET",
         body: str = "",
-        headers: Mapping[str, str] = {},
+        headers: Mapping[str, str] = None,
     ) -> DAVResponse:
         """
         Actually sends the request, and does the authentication
         """
+        if headers is None:
+            headers = {}
+
         combined_headers = self.headers.copy()
         combined_headers.update(headers)
         if (body is None or body == "") and "Content-Type" in combined_headers: