From d50eef989a4c8a7ed95eb25ce948e70e85b4c15c Mon Sep 17 00:00:00 2001
From: Marius Kriegerowski <marius.kriegerowski@gmail.com>
Date: Sat, 20 Mar 2021 18:01:16 +0100
Subject: [PATCH] Fix mutable in signature

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

diff --git a/hbmqtt/client.py b/hbmqtt/client.py
index 4f24b79..3f54bba 100644
--- a/hbmqtt/client.py
+++ b/hbmqtt/client.py
@@ -135,7 +135,7 @@ class MQTTClient:
         cafile=None,
         capath=None,
         cadata=None,
-        extra_headers={},
+        extra_headers=None,
     ):
         """
         Connect to a remote broker.
@@ -154,6 +154,9 @@ class MQTTClient:
         :raise: :class:`hbmqtt.client.ConnectException` if connection fails
         """
 
+        if extra_headers is None:
+            extra_headers = {}
+
         self.session = self._initsession(uri, cleansession, cafile, capath, cadata)
         self.extra_headers = extra_headers
         self.logger.debug("Connect to: %s" % uri)