Missing mypy_extensions Upstream Dependency

[vladtco]

Describe the bug

The upstream dependency mypy-extensions was removed in the commit - 613ff72

Usage of this dependency in code -

mr_proper/mr_proper/utils/ast_pure.py

Line 6 in 4be4647

from mypy_extensions import TypedDict

To Reproduce

Steps to reproduce the behavior:

1. Install flake8-functions==0.0.5
2. Run it on any *.py file

Stack Trace

/usr/local/lib/python3.8/site-packages/flake8/plugins/manager.py:157: in load_plugin
    self._load()
/usr/local/lib/python3.8/site-packages/flake8/plugins/manager.py:134: in _load
    self._plugin = self.entry_point.load()
/usr/local/lib/python3.8/importlib/metadata.py:77: in load
    module = import_module(match.group('module'))
/usr/local/lib/python3.8/importlib/__init__.py:127: in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
<frozen importlib._bootstrap>:1014: in _gcd_import
    ???
<frozen importlib._bootstrap>:991: in _find_and_load
    ???
<frozen importlib._bootstrap>:975: in _find_and_load_unlocked
    ???
<frozen importlib._bootstrap>:671: in _load_unlocked
    ???
<frozen importlib._bootstrap_external>:783: in exec_module
    ???
<frozen importlib._bootstrap>:219: in _call_with_frames_removed
    ???
/usr/local/lib/python3.8/site-packages/flake8_functions/checker.py:6: in <module>
    from flake8_functions.function_purity import check_purity_of_functions
/usr/local/lib/python3.8/site-packages/flake8_functions/function_purity.py:5: in <module>
    from mr_proper.public_api import is_function_pure
/usr/local/lib/python3.8/site-packages/mr_proper/public_api.py:13: in <module>
    from mr_proper.utils.ast_pure import get_not_pure_internal_calls
/usr/local/lib/python3.8/site-packages/mr_proper/utils/ast_pure.py:6: in <module>
    from mypy_extensions import TypedDict
E   ModuleNotFoundError: No module named 'mypy_extensions'

During handling of the above exception, another exception occurred:
/usr/local/lib/python3.8/site-packages/pluggy/hooks.py:286: in __call__
    return self._hookexec(self, self.get_hookimpls(), kwargs)
/usr/local/lib/python3.8/site-packages/pluggy/manager.py:93: in _hookexec
    return self._inner_hookexec(hook, methods, kwargs)
/usr/local/lib/python3.8/site-packages/pluggy/manager.py:84: in <lambda>
    self._inner_hookexec = lambda hook, methods, kwargs: hook.multicall(
/usr/local/lib/python3.8/site-packages/_pytest/runner.py:171: in pytest_runtest_call
    raise e
/usr/local/lib/python3.8/site-packages/_pytest/runner.py:163: in pytest_runtest_call
    item.runtest()
/usr/local/lib/python3.8/site-packages/pytest_flake8.py:120: in runtest
    found_errors, out, err = call(
/usr/local/lib/python3.8/site-packages/py/_io/capture.py:150: in call
    res = func(*args, **kwargs)
/usr/local/lib/python3.8/site-packages/pytest_flake8.py:203: in check_file
    app.find_plugins(config_finder)
/usr/local/lib/python3.8/site-packages/flake8/main/application.py:159: in find_plugins
    self.check_plugins.load_plugins()
/usr/local/lib/python3.8/site-packages/flake8/plugins/manager.py:415: in load_plugins
    plugins = list(self.manager.map(load_plugin))
/usr/local/lib/python3.8/site-packages/flake8/plugins/manager.py:302: in map
    yield func(self.plugins[name], *args, **kwargs)
/usr/local/lib/python3.8/site-packages/flake8/plugins/manager.py:413: in load_plugin
    return plugin.load_plugin()
/usr/local/lib/python3.8/site-packages/flake8/plugins/manager.py:164: in load_plugin
    raise failed_to_load
E   flake8.exceptions.FailedToLoadPlugin: Flake8 failed to load plugin "CFQ" due to No module named 'mypy_extensions'.

[korneevm]

Fixed thanks to @KyleKing