We are currently solving the following issue within our repository. Here is the issue text:
--- BEGIN ISSUE ---
Add support for Py 3.9
With Py 3.9 out, we should add it to the tests at some point. Maybe that can wait, until 3.9.x, x>0 is out, though

Need to check, if all the job thingies work out, as APS doesn't support py3.9 yet and there has been a [report](https://t.me/pythontelegrambotgroup/382731) that it doesn't work (with PTB).

On a related note: APS seems to be [preparing for v4.0](https://github.com/agronholm/apscheduler/issues/465), which will break some stuff, but also supports py3.9 and even uses the new ZoneInfo (also backporting to py3.6+), lifting the restriction to use `pytz` timezones. I already subscribed to releases. I guess updating APS in PTB should be done only when 4.x, x>0 is out and we're doing breaking things anyway …

--- 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 #!/usr/bin/env python
2 """The setup and build script for the python-telegram-bot library."""
3 
4 import codecs
5 import os
6 import sys
7 
8 from setuptools import setup, find_packages
9 
10 
11 def requirements():
12     """Build the requirements list for this project"""
13     requirements_list = []
14 
15     with open('requirements.txt') as requirements:
16         for install in requirements:
17             requirements_list.append(install.strip())
18 
19     return requirements_list
20 
21 
22 packages = find_packages(exclude=['tests*'])
23 requirements = requirements()
24 
25 # Allow for a package install to not use the vendored urllib3
26 UPSTREAM_URLLIB3_FLAG = '--with-upstream-urllib3'
27 if UPSTREAM_URLLIB3_FLAG in sys.argv:
28     sys.argv.remove(UPSTREAM_URLLIB3_FLAG)
29     requirements.append('urllib3 >= 1.19.1')
30     packages = [x for x in packages if not x.startswith('telegram.vendor.ptb_urllib3')]
31 
32 with codecs.open('README.rst', 'r', 'utf-8') as fd:
33     fn = os.path.join('telegram', 'version.py')
34     with open(fn) as fh:
35         code = compile(fh.read(), fn, 'exec')
36         exec(code)
37 
38     setup(name='python-telegram-bot',
39           version=__version__,
40           author='Leandro Toledo',
41           author_email='devs@python-telegram-bot.org',
42           license='LGPLv3',
43           url='https://python-telegram-bot.org/',
44           keywords='python telegram bot api wrapper',
45           description="We have made you a wrapper you can't refuse",
46           long_description=fd.read(),
47           packages=packages,
48           install_requires=requirements,
49           extras_require={
50               'json': 'ujson',
51               'socks': 'PySocks'
52           },
53           include_package_data=True,
54           classifiers=[
55               'Development Status :: 5 - Production/Stable',
56               'Intended Audience :: Developers',
57               'License :: OSI Approved :: GNU Lesser General Public License v3 (LGPLv3)',
58               'Operating System :: OS Independent',
59               'Topic :: Software Development :: Libraries :: Python Modules',
60               'Topic :: Communications :: Chat',
61               'Topic :: Internet',
62               'Programming Language :: Python',
63               'Programming Language :: Python :: 3',
64               'Programming Language :: Python :: 3.6',
65               'Programming Language :: Python :: 3.7',
66               'Programming Language :: Python :: 3.8',
67           ],)
68
```
--- 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
@@ -64,4 +64,5 @@
               'Programming Language :: Python :: 3.6',
               'Programming Language :: Python :: 3.7',
               'Programming Language :: Python :: 3.8',
+              'Programming Language :: Python :: 3.9',
           ],)

{"golden_diff": "diff --git a/setup.py b/setup.py\n--- a/setup.py\n+++ b/setup.py\n@@ -64,4 +64,5 @@\n               'Programming Language :: Python :: 3.6',\n               'Programming Language :: Python :: 3.7',\n               'Programming Language :: Python :: 3.8',\n+              'Programming Language :: Python :: 3.9',\n           ],)\n", "issue": "Add support for Py 3.9\nWith Py 3.9 out, we should add it to the tests at some point. Maybe that can wait, until 3.9.x, x>0 is out, though\r\n\r\nNeed to check, if all the job thingies work out, as APS doesn't support py3.9 yet and there has been a [report](https://t.me/pythontelegrambotgroup/382731) that it doesn't work (with PTB).\r\n\r\nOn a related note: APS seems to be [preparing for v4.0](https://github.com/agronholm/apscheduler/issues/465), which will break some stuff, but also supports py3.9 and even uses the new ZoneInfo (also backporting to py3.6+), lifting the restriction to use `pytz` timezones. I already subscribed to releases. I guess updating APS in PTB should be done only when 4.x, x>0 is out and we're doing breaking things anyway \u2026\n", "before_files": [{"content": "#!/usr/bin/env python\n\"\"\"The setup and build script for the python-telegram-bot library.\"\"\"\n\nimport codecs\nimport os\nimport sys\n\nfrom setuptools import setup, find_packages\n\n\ndef requirements():\n    \"\"\"Build the requirements list for this project\"\"\"\n    requirements_list = []\n\n    with open('requirements.txt') as requirements:\n        for install in requirements:\n            requirements_list.append(install.strip())\n\n    return requirements_list\n\n\npackages = find_packages(exclude=['tests*'])\nrequirements = requirements()\n\n# Allow for a package install to not use the vendored urllib3\nUPSTREAM_URLLIB3_FLAG = '--with-upstream-urllib3'\nif UPSTREAM_URLLIB3_FLAG in sys.argv:\n    sys.argv.remove(UPSTREAM_URLLIB3_FLAG)\n    requirements.append('urllib3 >= 1.19.1')\n    packages = [x for x in packages if not x.startswith('telegram.vendor.ptb_urllib3')]\n\nwith codecs.open('README.rst', 'r', 'utf-8') as fd:\n    fn = os.path.join('telegram', 'version.py')\n    with open(fn) as fh:\n        code = compile(fh.read(), fn, 'exec')\n        exec(code)\n\n    setup(name='python-telegram-bot',\n          version=__version__,\n          author='Leandro Toledo',\n          author_email='devs@python-telegram-bot.org',\n          license='LGPLv3',\n          url='https://python-telegram-bot.org/',\n          keywords='python telegram bot api wrapper',\n          description=\"We have made you a wrapper you can't refuse\",\n          long_description=fd.read(),\n          packages=packages,\n          install_requires=requirements,\n          extras_require={\n              'json': 'ujson',\n              'socks': 'PySocks'\n          },\n          include_package_data=True,\n          classifiers=[\n              'Development Status :: 5 - Production/Stable',\n              'Intended Audience :: Developers',\n              'License :: OSI Approved :: GNU Lesser General Public License v3 (LGPLv3)',\n              'Operating System :: OS Independent',\n              'Topic :: Software Development :: Libraries :: Python Modules',\n              'Topic :: Communications :: Chat',\n              'Topic :: Internet',\n              'Programming Language :: Python',\n              'Programming Language :: Python :: 3',\n              'Programming Language :: Python :: 3.6',\n              'Programming Language :: Python :: 3.7',\n              'Programming Language :: Python :: 3.8',\n          ],)\n", "path": "setup.py"}], "after_files": [{"content": "#!/usr/bin/env python\n\"\"\"The setup and build script for the python-telegram-bot library.\"\"\"\n\nimport codecs\nimport os\nimport sys\n\nfrom setuptools import setup, find_packages\n\n\ndef requirements():\n    \"\"\"Build the requirements list for this project\"\"\"\n    requirements_list = []\n\n    with open('requirements.txt') as requirements:\n        for install in requirements:\n            requirements_list.append(install.strip())\n\n    return requirements_list\n\n\npackages = find_packages(exclude=['tests*'])\nrequirements = requirements()\n\n# Allow for a package install to not use the vendored urllib3\nUPSTREAM_URLLIB3_FLAG = '--with-upstream-urllib3'\nif UPSTREAM_URLLIB3_FLAG in sys.argv:\n    sys.argv.remove(UPSTREAM_URLLIB3_FLAG)\n    requirements.append('urllib3 >= 1.19.1')\n    packages = [x for x in packages if not x.startswith('telegram.vendor.ptb_urllib3')]\n\nwith codecs.open('README.rst', 'r', 'utf-8') as fd:\n    fn = os.path.join('telegram', 'version.py')\n    with open(fn) as fh:\n        code = compile(fh.read(), fn, 'exec')\n        exec(code)\n\n    setup(name='python-telegram-bot',\n          version=__version__,\n          author='Leandro Toledo',\n          author_email='devs@python-telegram-bot.org',\n          license='LGPLv3',\n          url='https://python-telegram-bot.org/',\n          keywords='python telegram bot api wrapper',\n          description=\"We have made you a wrapper you can't refuse\",\n          long_description=fd.read(),\n          packages=packages,\n          install_requires=requirements,\n          extras_require={\n              'json': 'ujson',\n              'socks': 'PySocks'\n          },\n          include_package_data=True,\n          classifiers=[\n              'Development Status :: 5 - Production/Stable',\n              'Intended Audience :: Developers',\n              'License :: OSI Approved :: GNU Lesser General Public License v3 (LGPLv3)',\n              'Operating System :: OS Independent',\n              'Topic :: Software Development :: Libraries :: Python Modules',\n              'Topic :: Communications :: Chat',\n              'Topic :: Internet',\n              'Programming Language :: Python',\n              'Programming Language :: Python :: 3',\n              'Programming Language :: Python :: 3.6',\n              'Programming Language :: Python :: 3.7',\n              'Programming Language :: Python :: 3.8',\n              'Programming Language :: Python :: 3.9',\n          ],)\n", "path": "setup.py"}]}