We are currently solving the following issue within our repository. Here is the issue text:
--- BEGIN ISSUE ---
Missing py.typed declaration?
`mypy` is complaining about not being able to find type annotations for `httpx`: 

`error: Cannot find module named 'httpx'`

I'm somewhat new to using type annotations/static type checking in Python, but from the mypy documentation [here](https://mypy.readthedocs.io/en/latest/installed_packages.html#making-pep-561-compatible-packages) it looks like there may be a missing declaration in `setup.py`?

--- 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 # -*- coding: utf-8 -*-
3 
4 import os
5 import re
6 
7 from setuptools import setup
8 
9 
10 def get_version(package):
11     """
12     Return package version as listed in `__version__` in `init.py`.
13     """
14     with open(os.path.join(package, "__version__.py")) as f:
15         return re.search("__version__ = ['\"]([^'\"]+)['\"]", f.read()).group(1)
16 
17 
18 def get_long_description():
19     """
20     Return the README.
21     """
22     with open("README.md", encoding="utf8") as f:
23         return f.read()
24 
25 
26 def get_packages(package):
27     """
28     Return root package and all sub-packages.
29     """
30     return [
31         dirpath
32         for dirpath, dirnames, filenames in os.walk(package)
33         if os.path.exists(os.path.join(dirpath, "__init__.py"))
34     ]
35 
36 
37 setup(
38     name="httpx",
39     python_requires=">=3.6",
40     version=get_version("httpx"),
41     url="https://github.com/encode/httpx",
42     license="BSD",
43     description="The next generation HTTP client.",
44     long_description=get_long_description(),
45     long_description_content_type="text/markdown",
46     author="Tom Christie",
47     author_email="tom@tomchristie.com",
48     packages=get_packages("httpx"),
49     install_requires=[
50         "certifi",
51         "chardet==3.*",
52         "h11==0.8.*",
53         "h2==3.*",
54         "hstspreload",
55         "idna==2.*",
56         "rfc3986==1.*",
57     ],
58     classifiers=[
59         "Development Status :: 3 - Alpha",
60         "Environment :: Web Environment",
61         "Intended Audience :: Developers",
62         "License :: OSI Approved :: BSD License",
63         "Operating System :: OS Independent",
64         "Topic :: Internet :: WWW/HTTP",
65         "Programming Language :: Python :: 3",
66         "Programming Language :: Python :: 3.6",
67         "Programming Language :: Python :: 3.7",
68         "Programming Language :: Python :: 3.8",
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
@@ -45,6 +45,7 @@
     long_description_content_type="text/markdown",
     author="Tom Christie",
     author_email="tom@tomchristie.com",
+    package_data={"httpx": ["py.typed"]},
     packages=get_packages("httpx"),
     install_requires=[
         "certifi",

{"golden_diff": "diff --git a/setup.py b/setup.py\n--- a/setup.py\n+++ b/setup.py\n@@ -45,6 +45,7 @@\n     long_description_content_type=\"text/markdown\",\n     author=\"Tom Christie\",\n     author_email=\"tom@tomchristie.com\",\n+    package_data={\"httpx\": [\"py.typed\"]},\n     packages=get_packages(\"httpx\"),\n     install_requires=[\n         \"certifi\",\n", "issue": "Missing py.typed declaration?\n`mypy` is complaining about not being able to find type annotations for `httpx`: \r\n\r\n`error: Cannot find module named 'httpx'`\r\n\r\nI'm somewhat new to using type annotations/static type checking in Python, but from the mypy documentation [here](https://mypy.readthedocs.io/en/latest/installed_packages.html#making-pep-561-compatible-packages) it looks like there may be a missing declaration in `setup.py`?\n", "before_files": [{"content": "#!/usr/bin/env python\n# -*- coding: utf-8 -*-\n\nimport os\nimport re\n\nfrom setuptools import setup\n\n\ndef get_version(package):\n    \"\"\"\n    Return package version as listed in `__version__` in `init.py`.\n    \"\"\"\n    with open(os.path.join(package, \"__version__.py\")) as f:\n        return re.search(\"__version__ = ['\\\"]([^'\\\"]+)['\\\"]\", f.read()).group(1)\n\n\ndef get_long_description():\n    \"\"\"\n    Return the README.\n    \"\"\"\n    with open(\"README.md\", encoding=\"utf8\") as f:\n        return f.read()\n\n\ndef get_packages(package):\n    \"\"\"\n    Return root package and all sub-packages.\n    \"\"\"\n    return [\n        dirpath\n        for dirpath, dirnames, filenames in os.walk(package)\n        if os.path.exists(os.path.join(dirpath, \"__init__.py\"))\n    ]\n\n\nsetup(\n    name=\"httpx\",\n    python_requires=\">=3.6\",\n    version=get_version(\"httpx\"),\n    url=\"https://github.com/encode/httpx\",\n    license=\"BSD\",\n    description=\"The next generation HTTP client.\",\n    long_description=get_long_description(),\n    long_description_content_type=\"text/markdown\",\n    author=\"Tom Christie\",\n    author_email=\"tom@tomchristie.com\",\n    packages=get_packages(\"httpx\"),\n    install_requires=[\n        \"certifi\",\n        \"chardet==3.*\",\n        \"h11==0.8.*\",\n        \"h2==3.*\",\n        \"hstspreload\",\n        \"idna==2.*\",\n        \"rfc3986==1.*\",\n    ],\n    classifiers=[\n        \"Development Status :: 3 - Alpha\",\n        \"Environment :: Web Environment\",\n        \"Intended Audience :: Developers\",\n        \"License :: OSI Approved :: BSD License\",\n        \"Operating System :: OS Independent\",\n        \"Topic :: Internet :: WWW/HTTP\",\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)\n", "path": "setup.py"}], "after_files": [{"content": "#!/usr/bin/env python\n# -*- coding: utf-8 -*-\n\nimport os\nimport re\n\nfrom setuptools import setup\n\n\ndef get_version(package):\n    \"\"\"\n    Return package version as listed in `__version__` in `init.py`.\n    \"\"\"\n    with open(os.path.join(package, \"__version__.py\")) as f:\n        return re.search(\"__version__ = ['\\\"]([^'\\\"]+)['\\\"]\", f.read()).group(1)\n\n\ndef get_long_description():\n    \"\"\"\n    Return the README.\n    \"\"\"\n    with open(\"README.md\", encoding=\"utf8\") as f:\n        return f.read()\n\n\ndef get_packages(package):\n    \"\"\"\n    Return root package and all sub-packages.\n    \"\"\"\n    return [\n        dirpath\n        for dirpath, dirnames, filenames in os.walk(package)\n        if os.path.exists(os.path.join(dirpath, \"__init__.py\"))\n    ]\n\n\nsetup(\n    name=\"httpx\",\n    python_requires=\">=3.6\",\n    version=get_version(\"httpx\"),\n    url=\"https://github.com/encode/httpx\",\n    license=\"BSD\",\n    description=\"The next generation HTTP client.\",\n    long_description=get_long_description(),\n    long_description_content_type=\"text/markdown\",\n    author=\"Tom Christie\",\n    author_email=\"tom@tomchristie.com\",\n    package_data={\"httpx\": [\"py.typed\"]},\n    packages=get_packages(\"httpx\"),\n    install_requires=[\n        \"certifi\",\n        \"chardet==3.*\",\n        \"h11==0.8.*\",\n        \"h2==3.*\",\n        \"hstspreload\",\n        \"idna==2.*\",\n        \"rfc3986==1.*\",\n    ],\n    classifiers=[\n        \"Development Status :: 3 - Alpha\",\n        \"Environment :: Web Environment\",\n        \"Intended Audience :: Developers\",\n        \"License :: OSI Approved :: BSD License\",\n        \"Operating System :: OS Independent\",\n        \"Topic :: Internet :: WWW/HTTP\",\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)\n", "path": "setup.py"}]}