From 7ee536e99fd9f8491a0185ddb6ddff71c6c4315c Mon Sep 17 00:00:00 2001
From: Dave Shawley <daveshawley@gmail.com>
Date: Wed, 24 Mar 2021 06:30:26 -0400
Subject: [PATCH] Fix test error.

---
 tests/test_mixins.py | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/tests/test_mixins.py b/tests/test_mixins.py
index f0955ca..6e86346 100644
--- a/tests/test_mixins.py
+++ b/tests/test_mixins.py
@@ -41,6 +41,14 @@ class ApplicationTests(AsyncTestCaseWithTimeout):
         super().setUp()
         self._environ = {}
 
+    def tearDown(self):
+        super().tearDown()
+        for name, value in self._environ.items():
+            if value is not None:
+                os.environ[name] = value
+            else:
+                os.environ.pop(name, None)
+
     def setenv(self, name, value):
         self._environ.setdefault(name, os.environ.pop(name, None))
         os.environ[name] = value