$ grep typing $(find -name '*.py' -not -path './.tox/*')

./openstack/config/loader.py:                # behavior and allows for much less typing.
./openstack/__init__.py:import typing
./openstack/__init__.py:        app_name=None,  # type: typing.Optional[str]
./openstack/__init__.py:        app_version=None,  # type: typing.Optional[str]
./openstack/tests/unit/test_resource.py:        # Test that we short-circuit any typing of a None value.
./openstack/tests/unit/test_resource.py:        # short-circuit the typing part of __get__ it would fail.
./openstack/tests/unit/test_resource.py:    # The code path for typing after a raw value has been found is the same.