diff --git a/tests/integration/test_httpx.py b/tests/integration/test_httpx.py
index cad7318..1d4eb9c 100644
--- a/tests/integration/test_httpx.py
+++ b/tests/integration/test_httpx.py
@@ -1,4 +1,3 @@
-from unittest.mock import MagicMock
 import pytest
 import contextlib
 import os
@@ -194,6 +193,7 @@ def test_behind_proxy(do_request):
 def test_cookies(tmpdir, scheme, do_request):
     def client_cookies(client):
         return [c for c in client._client.cookies]
+
     def response_cookies(response):
         return [c for c in response.cookies]
 
@@ -204,25 +204,24 @@ def test_cookies(tmpdir, scheme, do_request):
     testfile = str(tmpdir.join("cookies.yml"))
     with vcr.use_cassette(testfile):
         r1 = client("GET", url + "/cookies/set?k1=v1&k2=v2")
-        assert response_cookies(r1.history[0]) == ['k1', 'k2']
+        assert response_cookies(r1.history[0]) == ["k1", "k2"]
         assert response_cookies(r1) == []
 
         r2 = client("GET", url + "/cookies")
         assert len(r2.json()["cookies"]) == 2
 
-        assert client_cookies(client) == ['k1', 'k2']
-
+        assert client_cookies(client) == ["k1", "k2"]
 
     new_client = do_request()
     assert client_cookies(new_client) == []
 
     with vcr.use_cassette(testfile) as cassette:
         cassette_response = new_client("GET", url + "/cookies/set?k1=v1&k2=v2")
-        assert response_cookies(cassette_response.history[0]) == ['k1', 'k2']
+        assert response_cookies(cassette_response.history[0]) == ["k1", "k2"]
         assert response_cookies(cassette_response) == []
 
         assert cassette.play_count == 2
-        assert client_cookies(new_client) == ['k1', 'k2']
+        assert client_cookies(new_client) == ["k1", "k2"]
 
 
 def test_relative_redirects(tmpdir, scheme, do_request):
@@ -239,4 +238,3 @@ def test_relative_redirects(tmpdir, scheme, do_request):
         assert response.json()["url"].endswith("get")
 
         assert cassette.play_count == 3
-
diff --git a/tox.ini b/tox.ini
index 055c13e..def257e 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,6 +1,6 @@
 [tox]
 skip_missing_interpreters=true
-envlist = 
+envlist =
   cov-clean,
   lint,
   {py35,py36,py37,py38}-{requests,httplib2,urllib3,tornado4,boto3,aiohttp,httpx},
@@ -18,7 +18,7 @@ commands = coverage erase
 [testenv:cov-report]
 deps = coverage
 skip_install=true
-commands = 
+commands =
   coverage html
   coverage report --fail-under=90
 
@@ -30,8 +30,8 @@ commands =
     flake8 --version
     flake8 --exclude=./docs/conf.py,./.tox/
     pyflakes ./docs/conf.py
-deps = 
-  flake8 
+deps =
+  flake8
   black
 
 [testenv:docs]
diff --git a/vcr/stubs/httpx_stubs.py b/vcr/stubs/httpx_stubs.py
index b2d662b..68ee38e 100644
--- a/vcr/stubs/httpx_stubs.py
+++ b/vcr/stubs/httpx_stubs.py
@@ -2,7 +2,6 @@ import functools
 import logging
 from unittest.mock import patch, MagicMock
 
-from yarl import URL
 import httpx
 from vcr.request import Request as VcrRequest
 from vcr.errors import CannotOverwriteExistingCassetteException