We are currently solving the following issue within our repository. Here is the issue text:
--- BEGIN ISSUE ---
Use extra for asyncio dependencies
Hello!  The latest release for this library pulls in aiohttp and its dependencies unconditionally, which adds non-trivial burden to projects that don’t need it.  Would you consider using a packaging extra so that people can opt-in?

--- END ISSUE ---

Below are some code segments, each from a relevant file. One or more of these files may contain bugs.
--- BEGIN FILES ---
Path: `setup.py`
Content:
```
1 # Copyright 2014 Google Inc.
2 #
3 # Licensed under the Apache License, Version 2.0 (the "License");
4 # you may not use this file except in compliance with the License.
5 # You may obtain a copy of the License at
6 #
7 #      http://www.apache.org/licenses/LICENSE-2.0
8 #
9 # Unless required by applicable law or agreed to in writing, software
10 # distributed under the License is distributed on an "AS IS" BASIS,
11 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 # See the License for the specific language governing permissions and
13 # limitations under the License.
14 
15 import io
16 
17 from setuptools import find_packages
18 from setuptools import setup
19 
20 
21 DEPENDENCIES = (
22     "cachetools>=2.0.0,<5.0",
23     "pyasn1-modules>=0.2.1",
24     # rsa==4.5 is the last version to support 2.7
25     # https://github.com/sybrenstuvel/python-rsa/issues/152#issuecomment-643470233
26     'rsa<4.6; python_version < "3.5"',
27     'rsa>=3.1.4,<5; python_version >= "3.5"',
28     "setuptools>=40.3.0",
29     "six>=1.9.0",
30     'aiohttp >= 3.6.2, < 4.0.0dev; python_version>="3.6"',
31 )
32 
33 
34 with io.open("README.rst", "r") as fh:
35     long_description = fh.read()
36 
37 version = "1.22.0"
38 
39 setup(
40     name="google-auth",
41     version=version,
42     author="Google Cloud Platform",
43     author_email="googleapis-packages@google.com",
44     description="Google Authentication Library",
45     long_description=long_description,
46     url="https://github.com/googleapis/google-auth-library-python",
47     packages=find_packages(exclude=("tests*", "system_tests*")),
48     namespace_packages=("google",),
49     install_requires=DEPENDENCIES,
50     python_requires=">=2.7,!=3.0.*,!=3.1.*,!=3.2.*,!=3.3.*",
51     license="Apache 2.0",
52     keywords="google auth oauth client",
53     classifiers=[
54         "Programming Language :: Python :: 2",
55         "Programming Language :: Python :: 2.7",
56         "Programming Language :: Python :: 3",
57         "Programming Language :: Python :: 3.5",
58         "Programming Language :: Python :: 3.6",
59         "Programming Language :: Python :: 3.7",
60         "Programming Language :: Python :: 3.8",
61         "Development Status :: 5 - Production/Stable",
62         "Intended Audience :: Developers",
63         "License :: OSI Approved :: Apache Software License",
64         "Operating System :: POSIX",
65         "Operating System :: Microsoft :: Windows",
66         "Operating System :: MacOS :: MacOS X",
67         "Operating System :: OS Independent",
68         "Topic :: Internet :: WWW/HTTP",
69     ],
70 )
71
```
--- END FILES ---

Please first localize the bug based on the issue statement, and then generate a patch according to the `git diff` format fenced by three backticks.

Here is an example:

```diff
diff --git a/examples/server_async.py b/examples/server_async.py
--- a/examples/server_async.py
+++ b/examples/server_async.py
@@ -313,4 +313,4 @@
 
 
 if __name__ == "__main__":
-    asyncio.run(run_async_server("."), debug=True)
+    asyncio.run(run_async_server(), debug=True)
diff --git a/examples/server_sync.py b/examples/server_sync.py
--- a/examples/server_sync.py
+++ b/examples/server_sync.py
@@ -313,5 +313,5 @@
 
 
 if __name__ == "__main__":
-    server = run_sync_server(".")
+    server = run_sync_server()
     server.shutdown()

```

diff --git a/setup.py b/setup.py
--- a/setup.py
+++ b/setup.py
@@ -27,9 +27,9 @@
     'rsa>=3.1.4,<5; python_version >= "3.5"',
     "setuptools>=40.3.0",
     "six>=1.9.0",
-    'aiohttp >= 3.6.2, < 4.0.0dev; python_version>="3.6"',
 )
 
+extras = {"aiohttp": "aiohttp >= 3.6.2, < 4.0.0dev; python_version>='3.6'"}
 
 with io.open("README.rst", "r") as fh:
     long_description = fh.read()
@@ -47,6 +47,7 @@
     packages=find_packages(exclude=("tests*", "system_tests*")),
     namespace_packages=("google",),
     install_requires=DEPENDENCIES,
+    extras_require=extras,
     python_requires=">=2.7,!=3.0.*,!=3.1.*,!=3.2.*,!=3.3.*",
     license="Apache 2.0",
     keywords="google auth oauth client",

{"golden_diff": "diff --git a/setup.py b/setup.py\n--- a/setup.py\n+++ b/setup.py\n@@ -27,9 +27,9 @@\n     'rsa>=3.1.4,<5; python_version >= \"3.5\"',\n     \"setuptools>=40.3.0\",\n     \"six>=1.9.0\",\n-    'aiohttp >= 3.6.2, < 4.0.0dev; python_version>=\"3.6\"',\n )\n \n+extras = {\"aiohttp\": \"aiohttp >= 3.6.2, < 4.0.0dev; python_version>='3.6'\"}\n \n with io.open(\"README.rst\", \"r\") as fh:\n     long_description = fh.read()\n@@ -47,6 +47,7 @@\n     packages=find_packages(exclude=(\"tests*\", \"system_tests*\")),\n     namespace_packages=(\"google\",),\n     install_requires=DEPENDENCIES,\n+    extras_require=extras,\n     python_requires=\">=2.7,!=3.0.*,!=3.1.*,!=3.2.*,!=3.3.*\",\n     license=\"Apache 2.0\",\n     keywords=\"google auth oauth client\",\n", "issue": "Use extra for asyncio dependencies\nHello!  The latest release for this library pulls in aiohttp and its dependencies unconditionally, which adds non-trivial burden to projects that don\u2019t need it.  Would you consider using a packaging extra so that people can opt-in?\n", "before_files": [{"content": "# Copyright 2014 Google Inc.\n#\n# Licensed under the Apache License, Version 2.0 (the \"License\");\n# you may not use this file except in compliance with the License.\n# You may obtain a copy of the License at\n#\n#      http://www.apache.org/licenses/LICENSE-2.0\n#\n# Unless required by applicable law or agreed to in writing, software\n# distributed under the License is distributed on an \"AS IS\" BASIS,\n# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.\n# See the License for the specific language governing permissions and\n# limitations under the License.\n\nimport io\n\nfrom setuptools import find_packages\nfrom setuptools import setup\n\n\nDEPENDENCIES = (\n    \"cachetools>=2.0.0,<5.0\",\n    \"pyasn1-modules>=0.2.1\",\n    # rsa==4.5 is the last version to support 2.7\n    # https://github.com/sybrenstuvel/python-rsa/issues/152#issuecomment-643470233\n    'rsa<4.6; python_version < \"3.5\"',\n    'rsa>=3.1.4,<5; python_version >= \"3.5\"',\n    \"setuptools>=40.3.0\",\n    \"six>=1.9.0\",\n    'aiohttp >= 3.6.2, < 4.0.0dev; python_version>=\"3.6\"',\n)\n\n\nwith io.open(\"README.rst\", \"r\") as fh:\n    long_description = fh.read()\n\nversion = \"1.22.0\"\n\nsetup(\n    name=\"google-auth\",\n    version=version,\n    author=\"Google Cloud Platform\",\n    author_email=\"googleapis-packages@google.com\",\n    description=\"Google Authentication Library\",\n    long_description=long_description,\n    url=\"https://github.com/googleapis/google-auth-library-python\",\n    packages=find_packages(exclude=(\"tests*\", \"system_tests*\")),\n    namespace_packages=(\"google\",),\n    install_requires=DEPENDENCIES,\n    python_requires=\">=2.7,!=3.0.*,!=3.1.*,!=3.2.*,!=3.3.*\",\n    license=\"Apache 2.0\",\n    keywords=\"google auth oauth client\",\n    classifiers=[\n        \"Programming Language :: Python :: 2\",\n        \"Programming Language :: Python :: 2.7\",\n        \"Programming Language :: Python :: 3\",\n        \"Programming Language :: Python :: 3.5\",\n        \"Programming Language :: Python :: 3.6\",\n        \"Programming Language :: Python :: 3.7\",\n        \"Programming Language :: Python :: 3.8\",\n        \"Development Status :: 5 - Production/Stable\",\n        \"Intended Audience :: Developers\",\n        \"License :: OSI Approved :: Apache Software License\",\n        \"Operating System :: POSIX\",\n        \"Operating System :: Microsoft :: Windows\",\n        \"Operating System :: MacOS :: MacOS X\",\n        \"Operating System :: OS Independent\",\n        \"Topic :: Internet :: WWW/HTTP\",\n    ],\n)\n", "path": "setup.py"}], "after_files": [{"content": "# Copyright 2014 Google Inc.\n#\n# Licensed under the Apache License, Version 2.0 (the \"License\");\n# you may not use this file except in compliance with the License.\n# You may obtain a copy of the License at\n#\n#      http://www.apache.org/licenses/LICENSE-2.0\n#\n# Unless required by applicable law or agreed to in writing, software\n# distributed under the License is distributed on an \"AS IS\" BASIS,\n# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.\n# See the License for the specific language governing permissions and\n# limitations under the License.\n\nimport io\n\nfrom setuptools import find_packages\nfrom setuptools import setup\n\n\nDEPENDENCIES = (\n    \"cachetools>=2.0.0,<5.0\",\n    \"pyasn1-modules>=0.2.1\",\n    # rsa==4.5 is the last version to support 2.7\n    # https://github.com/sybrenstuvel/python-rsa/issues/152#issuecomment-643470233\n    'rsa<4.6; python_version < \"3.5\"',\n    'rsa>=3.1.4,<5; python_version >= \"3.5\"',\n    \"setuptools>=40.3.0\",\n    \"six>=1.9.0\",\n)\n\nextras = {\"aiohttp\": \"aiohttp >= 3.6.2, < 4.0.0dev; python_version>='3.6'\"}\n\nwith io.open(\"README.rst\", \"r\") as fh:\n    long_description = fh.read()\n\nversion = \"1.22.0\"\n\nsetup(\n    name=\"google-auth\",\n    version=version,\n    author=\"Google Cloud Platform\",\n    author_email=\"googleapis-packages@google.com\",\n    description=\"Google Authentication Library\",\n    long_description=long_description,\n    url=\"https://github.com/googleapis/google-auth-library-python\",\n    packages=find_packages(exclude=(\"tests*\", \"system_tests*\")),\n    namespace_packages=(\"google\",),\n    install_requires=DEPENDENCIES,\n    extras_require=extras,\n    python_requires=\">=2.7,!=3.0.*,!=3.1.*,!=3.2.*,!=3.3.*\",\n    license=\"Apache 2.0\",\n    keywords=\"google auth oauth client\",\n    classifiers=[\n        \"Programming Language :: Python :: 2\",\n        \"Programming Language :: Python :: 2.7\",\n        \"Programming Language :: Python :: 3\",\n        \"Programming Language :: Python :: 3.5\",\n        \"Programming Language :: Python :: 3.6\",\n        \"Programming Language :: Python :: 3.7\",\n        \"Programming Language :: Python :: 3.8\",\n        \"Development Status :: 5 - Production/Stable\",\n        \"Intended Audience :: Developers\",\n        \"License :: OSI Approved :: Apache Software License\",\n        \"Operating System :: POSIX\",\n        \"Operating System :: Microsoft :: Windows\",\n        \"Operating System :: MacOS :: MacOS X\",\n        \"Operating System :: OS Independent\",\n        \"Topic :: Internet :: WWW/HTTP\",\n    ],\n)\n", "path": "setup.py"}]}